{"id":503,"date":"2020-01-12T20:42:48","date_gmt":"2020-01-12T20:42:48","guid":{"rendered":"http:\/\/localhost\/?post_type=knowledgebase&#038;p=503"},"modified":"2024-02-07T13:56:26","modified_gmt":"2024-02-07T13:56:26","slug":"practice-question-sequence-and-series","status":"publish","type":"knowledgebase","link":"https:\/\/ibalmaths.com\/index.php\/ibdp-math-hl-2\/sequence-and-series\/practice-question-sequence-and-series\/","title":{"rendered":"Sequence and Series &#8211; Practice Questions"},"content":{"rendered":"<p>Q1. Suppose \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>&#945;<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>&#946;<\/mi><\/math>\r\n are the roots of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mi>x<\/mi><mn>2<\/mn><\/msup><mo>+<\/mo><mi>k<\/mi><mi>x<\/mi><mo>+<\/mo><mn>1<\/mn><mo>=<\/mo><mn>0<\/mn><\/math>\r\n and \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>&#947;<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>&#948;<\/mi><\/math>\r\n are the roots of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mi>x<\/mi><mn>2<\/mn><\/msup><mo>+<\/mo><mi>x<\/mi><mo>+<\/mo><mi>k<\/mi><mo>=<\/mo><mn>0<\/mn><\/math>\r\n .<\/p>\r\n<p><strong>(a)<\/strong> if \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>&#945;<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>&#946;<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>&#947;<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>&#948;<\/mi><\/math>\r\n are in arithmetic sequence, then find the common difference of this arithmetic sequence in terms of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><\/math>\r\n ,<\/p>\r\n<p><strong> (b)<\/strong> if \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>&#945;<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>&#946;<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>&#947;<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>&#948;<\/mi><\/math>\r\n are in geometric sequence, then find the common ratio of this geometric sequence in terms of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><\/math>\r\n .<\/p>\r\n<div id=\"link1-link-503\" class=\"sh-link link1-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link1', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link1-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link1-content-503\" class=\"sh-content link1-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>Coming soon<br \/>\r\n<\/div>\r\n<p>Q2. If the third term of a geometric sequence is 3 , then find the product of the first 5 terms?<\/p>\r\n<div id=\"link2-link-503\" class=\"sh-link link2-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link2', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link2-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link2-content-503\" class=\"sh-content link2-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>Coming soon<br \/>\r\n<\/div>\r\n<p>Q3. The sum of an infinite geometric series with first term \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>x<\/mi><\/math>\r\n is equal to 3. Show that \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mo>&#8211;<\/mo><mn>6<\/mn><mo>&#60;<\/mo><mi>x<\/mi><mo>&#60;<\/mo><mn>0<\/mn><\/math>\r\n .<\/p>\r\n<div id=\"link3-link-503\" class=\"sh-link link3-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link3', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link3-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link3-content-503\" class=\"sh-content link3-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q4. Find the coefficient of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mi>x<\/mi><mn>49<\/mn><\/msup><\/math>\r\n \u00a0in the polynomial \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>p<\/mi><mo>(<\/mo><mi>x<\/mi><mo>)<\/mo><mo>=<\/mo><mo>(<\/mo><mi>x<\/mi><mo>&#8211;<\/mo><mn>1<\/mn><mo>)<\/mo><mo>(<\/mo><mi>x<\/mi><mo>&#8211;<\/mo><mn>2<\/mn><mo>)<\/mo><mo>(<\/mo><mi>x<\/mi><mo>&#8211;<\/mo><mn>3<\/mn><mo>)<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>(<\/mo><mi>x<\/mi><mo>&#8211;<\/mo><mn>50<\/mn><mo>)<\/mo><\/math>\r\n .<\/p>\r\n<div id=\"link4-link-503\" class=\"sh-link link4-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link4', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link4-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link4-content-503\" class=\"sh-content link4-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q5. If \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mn>1<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><msub><mi>S<\/mi><mn>2<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><msub><mi>S<\/mi><mn>3<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><msub><mi>S<\/mi><mi>n<\/mi><\/msub><\/math>\r\n \u00a0are the sum of infinite geometric series whose first terms are \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>2<\/mn><mo>,<\/mo><mn>3<\/mn><mo>,<\/mo><mn>4<\/mn><mo>,<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>(<\/mo><mi>n<\/mi><mo>&#8211;<\/mo><mn>1<\/mn><mo>)<\/mo><\/math>\r\n \u00a0and whose common ratios are<\/p>\r\n<p>\r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mfrac><mn>1<\/mn><mn>3<\/mn><\/mfrac><mo>,<\/mo><mfrac><mn>1<\/mn><mn>4<\/mn><\/mfrac><mo>,<\/mo><mfrac><mn>1<\/mn><mn>5<\/mn><\/mfrac><mo>,<\/mo><mo>&#160;<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mfrac><mn>1<\/mn><mi>n<\/mi><\/mfrac><\/math>\r\n \u00a0respectively then find the value of\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mn>1<\/mn><\/msub><mo>&#160;<\/mo><mo>+<\/mo><mo>&#160;<\/mo><msub><mi>S<\/mi><mn>2<\/mn><\/msub><mo>+<\/mo><msub><mi>S<\/mi><mn>3<\/mn><\/msub><mo>+<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>+<\/mo><msub><mi>S<\/mi><mrow><mn>2<\/mn><mi>n<\/mi><\/mrow><\/msub><\/math>\r\n .<\/p>\r\n<div id=\"link5-link-503\" class=\"sh-link link5-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link5', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link5-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link5-content-503\" class=\"sh-content link5-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q6. Find\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>a<\/mi><\/math>\r\n in terms of\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>c<\/mi><\/math>\r\n \u00a0if<img loading=\"lazy\" decoding=\"async\" class=\"aligncenter  wp-image-2240\" src=\"http:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/Screenshot-2024-02-07-204903.png\" alt=\"\" width=\"203\" height=\"27\" srcset=\"https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/Screenshot-2024-02-07-204903.png 443w, https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/Screenshot-2024-02-07-204903-300x40.png 300w\" sizes=\"auto, (max-width: 203px) 100vw, 203px\" \/> \u00a0are in arithmetic sequence.<\/p>\r\n<div id=\"link6-link-503\" class=\"sh-link link6-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link6', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link6-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link6-content-503\" class=\"sh-content link6-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q7.\u00a0Find the value of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>x<\/mi><\/math>\r\n if\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>ln<\/mi><mo>(<\/mo><msup><mn>3<\/mn><mi>x<\/mi><\/msup><mo>&#8211;<\/mo><mn>1<\/mn><mo>)<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mi>ln<\/mi><mo>(<\/mo><msup><mn>3<\/mn><mi>x<\/mi><\/msup><mo>+<\/mo><mn>1<\/mn><mo>)<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mi>ln<\/mi><mo>(<\/mo><msup><mn>3<\/mn><mrow><mi>x<\/mi><mo>+<\/mo><mn>1<\/mn><\/mrow><\/msup><mo>&#8211;<\/mo><mn>1<\/mn><mo>)<\/mo><\/math>\r\n \u00a0are in arithmetic sequence.<\/p>\r\n<div id=\"link7-link-503\" class=\"sh-link link7-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link7', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link7-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link7-content-503\" class=\"sh-content link7-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q8. Find the sum to\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n \u00a0terms of the series:\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mfrac><mn>3<\/mn><mn>2<\/mn><\/mfrac><mo>+<\/mo><mfrac><mn>5<\/mn><mn>4<\/mn><\/mfrac><mo>+<\/mo><mfrac><mn>9<\/mn><mn>8<\/mn><\/mfrac><mo>+<\/mo><mfrac><mn>17<\/mn><mn>16<\/mn><\/mfrac><mo>+<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><\/math>\r\n<\/p>\r\n<div id=\"link8-link-503\" class=\"sh-link link8-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link8', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link8-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link8-content-503\" class=\"sh-content link8-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q9.\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>ln<\/mi><mi>a<\/mi><mo>&#8211;<\/mo><mi>ln<\/mi><mn>2<\/mn><mi>b<\/mi><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mi>ln<\/mi><mn>2<\/mn><mi>b<\/mi><mo>&#8211;<\/mo><mi>ln<\/mi><mn>3<\/mn><mi>c<\/mi><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mi>ln<\/mi><mn>3<\/mn><mi>c<\/mi><mo>&#8211;<\/mo><mi>ln<\/mi><mi>a<\/mi><\/math>\r\n \u00a0are in arithmetic sequence. If\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>a<\/mi><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mi>b<\/mi><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mi>c<\/mi><\/math>\r\n \u00a0<\/p>\r\n<p>are in geometric sequence, show that\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>a<\/mi><mo>=<\/mo><mfrac><mrow><mn>9<\/mn><mi>c<\/mi><\/mrow><mn>4<\/mn><\/mfrac><\/math>\r\n .<\/p>\r\n<div id=\"link9-link-503\" class=\"sh-link link9-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link9', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link9-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link9-content-503\" class=\"sh-content link9-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q10. Two arithmetic sequences have the sum of their \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n<\/p>\r\n<p>terms in the ratio\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>3<\/mn><mi>n<\/mi><mo>:<\/mo><mo>(<\/mo><mn>2<\/mn><mi>n<\/mi><mo>&#8211;<\/mo><mn>1<\/mn><mo>)<\/mo><\/math>\r\n \u00a0. Find the ratio of their 23<sup>rd<\/sup> terms.<\/p>\r\n<div id=\"link10-link-503\" class=\"sh-link link10-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link10', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link10-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link10-content-503\" class=\"sh-content link10-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q11. Show that the sum to \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n terms of the series\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>2<\/mn><mo>+<\/mo><mfrac><mn>8<\/mn><mn>3<\/mn><\/mfrac><mo>+<\/mo><mfrac><mn>26<\/mn><mn>9<\/mn><\/mfrac><mo>+<\/mo><mfrac><mn>80<\/mn><mn>27<\/mn><\/mfrac><mo>+<\/mo><mfrac><mn>242<\/mn><mn>81<\/mn><\/mfrac><mo>+<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><\/math>\r\n \u00a0is\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>3<\/mn><mi>n<\/mi><mo>&#8211;<\/mo><mfrac><mn>3<\/mn><mn>2<\/mn><\/mfrac><mo>+<\/mo><mfrac><mn>1<\/mn><mrow><mn>2<\/mn><mo>&#215;<\/mo><msup><mn>3<\/mn><mrow><mi>n<\/mi><mo>&#8211;<\/mo><mn>1<\/mn><\/mrow><\/msup><\/mrow><\/mfrac><\/math>\r\n \u00a0.<\/p>\r\n<div id=\"link11-link-503\" class=\"sh-link link11-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link11', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link11-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link11-content-503\" class=\"sh-content link11-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q12. If\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>S<\/mi><mo>=<\/mo><mfrac><mn>1<\/mn><mn>4<\/mn><\/mfrac><mo>+<\/mo><mfrac><mn>1<\/mn><msup><mn>4<\/mn><mn>2<\/mn><\/msup><\/mfrac><mo>+<\/mo><mfrac><mn>1<\/mn><msup><mn>4<\/mn><mn>3<\/mn><\/msup><\/mfrac><mo>+<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>&#8734;<\/mo><\/math>\r\n \u00a0, then find the value of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mfenced><mrow><mn>0<\/mn><mo>.<\/mo><mn>5<\/mn><\/mrow><\/mfenced><mrow><msub><mi>log<\/mi><mn>3<\/mn><\/msub><mfenced><mi>S<\/mi><\/mfenced><\/mrow><\/msup><\/math>\r\n \u00a0.<\/p>\r\n<div id=\"link12-link-503\" class=\"sh-link link12-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link12', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link12-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link12-content-503\" class=\"sh-content link12-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q13.\u00a0Find the values of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>a<\/mi><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mi>b<\/mi><\/math>\r\n \u00a0and \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>c<\/mi><\/math>\r\n if<\/p>\r\n<p>\r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mfrac><mrow><msup><mi>x<\/mi><mn>11<\/mn><\/msup><mo>&#8211;<\/mo><mn>1<\/mn><\/mrow><mrow><mi>x<\/mi><mo>&#8211;<\/mo><mn>1<\/mn><\/mrow><\/mfrac><mo>=<\/mo><mn>1<\/mn><mo>+<\/mo><mi>a<\/mi><mi>x<\/mi><mo>+<\/mo><mi>b<\/mi><msup><mi>x<\/mi><mn>2<\/mn><\/msup><mo>+<\/mo><mi>c<\/mi><msup><mi>x<\/mi><mn>3<\/mn><\/msup><mo>+<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>+<\/mo><msup><mi>x<\/mi><mn>10<\/mn><\/msup><\/math>\r\n \u00a0 where\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>a<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>b<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>c<\/mi><mo>&#160;<\/mo><mo>&#8712;<\/mo><mi mathvariant=\"normal\">&#8477;<\/mi><\/math>\r\n .<\/p>\r\n<div id=\"link13-link-503\" class=\"sh-link link13-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link13', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link13-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link13-content-503\" class=\"sh-content link13-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q14.\u00a0If\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>a<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>b<\/mi><\/math>\r\n and\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>c<\/mi><\/math>\r\n \u00a0are the\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mi>m<\/mi><mrow><mi>t<\/mi><mi>h<\/mi><\/mrow><\/msup><mo>,<\/mo><mo>&#160;<\/mo><msup><mi>n<\/mi><mrow><mi>t<\/mi><mi>h<\/mi><\/mrow><\/msup><\/math>\r\n and \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mi>p<\/mi><mrow><mi>t<\/mi><mi>h<\/mi><\/mrow><\/msup><\/math>\r\n \u00a0terms respectively of an arithmetic sequence and also a geometric sequence, then show that the value of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mi>a<\/mi><mfenced><mrow><mi>b<\/mi><mo>&#8211;<\/mo><mi>c<\/mi><\/mrow><\/mfenced><\/msup><msup><mi>b<\/mi><mfenced><mrow><mi>c<\/mi><mo>&#8211;<\/mo><mi>a<\/mi><\/mrow><\/mfenced><\/msup><msup><mi>c<\/mi><mfenced><mrow><mi>a<\/mi><mo>&#8211;<\/mo><mi>b<\/mi><\/mrow><\/mfenced><\/msup><\/math>\r\n \u00a0is equal to 1.<\/p>\r\n<div id=\"link14-link-503\" class=\"sh-link link14-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link14', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link14-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link14-content-503\" class=\"sh-content link14-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q15. If \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>x<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>y<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>z<\/mi><\/math>\r\n \u00a0are respectively the\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mi>p<\/mi><mrow><mi>t<\/mi><mi>h<\/mi><\/mrow><\/msup><mo>,<\/mo><mo>&#160;<\/mo><msup><mi>q<\/mi><mrow><mi>t<\/mi><mi>h<\/mi><\/mrow><\/msup><mo>,<\/mo><mo>&#160;<\/mo><msup><mi>r<\/mi><mrow><mi>t<\/mi><mi>h<\/mi><\/mrow><\/msup><\/math>\r\n of a geometric sequence, then show that the value of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mfenced><mrow><mi>q<\/mi><mo>&#8211;<\/mo><mi>r<\/mi><\/mrow><\/mfenced><mi>ln<\/mi><mi>x<\/mi><mo>+<\/mo><mfenced><mrow><mi>r<\/mi><mo>&#8211;<\/mo><mi>p<\/mi><\/mrow><\/mfenced><mi>ln<\/mi><mi>y<\/mi><mo>+<\/mo><mfenced><mrow><mi>p<\/mi><mo>&#8211;<\/mo><mi>q<\/mi><\/mrow><\/mfenced><mi>ln<\/mi><mi>z<\/mi><\/math>\r\n \u00a0is equal to zero.<\/p>\r\n<div id=\"link15-link-503\" class=\"sh-link link15-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link15', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link15-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link15-content-503\" class=\"sh-content link15-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>coming soon<br \/>\r\n<\/div>\r\n<p>Q16. (a) A geometric progression has a second term of 12 and a sum to infinity of 54. Find the possible values of the first term of the progression. [4 marks]<\/p>\r\n<p>(b) The \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n th term of a progression is \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>p<\/mi><mo>+<\/mo><mi>q<\/mi><mi>n<\/mi><\/math>\r\n , where\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>p<\/mi><\/math>\r\n and\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>q<\/mi><\/math>\r\n are constants, and\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mi>n<\/mi><\/msub><\/math>\r\n is the sum of the first\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n terms.<br \/>\r\n(i) Find an expression, in terms of\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>p<\/mi><mo>,<\/mo><mo>&#160;<\/mo><mi>q<\/mi><\/math>\r\n and \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n , for \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mi>n<\/mi><\/msub><\/math>\r\n . [3 marks]<\/p>\r\n<p>(ii) Given that \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mn>4<\/mn><\/msub><mo>=<\/mo><mn>40<\/mn><\/math>\r\n and \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mn>6<\/mn><\/msub><mo>=<\/mo><mn>72<\/mn><\/math>\r\n , find the values of\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>p<\/mi><\/math>\r\n and \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>q<\/mi><\/math>\r\n . [2 marks]<\/p>\r\n<div id=\"link16-link-503\" class=\"sh-link link16-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link16', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link16-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link16-content-503\" class=\"sh-content link16-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignleft size-full wp-image-1826\" src=\"http:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-3.jpg\" alt=\"\" width=\"660\" height=\"613\" srcset=\"https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-3.jpg 660w, https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-3-300x279.jpg 300w\" sizes=\"auto, (max-width: 660px) 100vw, 660px\" \/><\/p>\r\n<p>&nbsp;<\/p>\r\n<p>&nbsp;<\/p>\r\n<p>&nbsp;<\/p>\r\n<p>&nbsp;<\/p>\r\n<p>&nbsp;<\/p>\r\n<p><\/div>\r\n<p>Q17. A sequence\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>a<\/mi><mn>1<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><msub><mi>a<\/mi><mrow><mn>2<\/mn><mo>&#160;<\/mo><\/mrow><\/msub><mo>,<\/mo><mo>&#160;<\/mo><msub><mi>a<\/mi><mn>3<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><\/math>\r\n is defined by<\/p>\r\n<p>\r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>a<\/mi><mn>1<\/mn><\/msub><mo>=<\/mo><mn>1<\/mn><mspace linebreak=\"newline\"><\/mspace><msub><mi>a<\/mi><mrow><mi>n<\/mi><mo>+<\/mo><mn>1<\/mn><\/mrow><\/msub><mo>=<\/mo><mfrac><mrow><mi>k<\/mi><mfenced><mrow><msub><mi>a<\/mi><mi>n<\/mi><\/msub><mo>+<\/mo><mn>1<\/mn><\/mrow><\/mfenced><\/mrow><msub><mi>a<\/mi><mi>n<\/mi><\/msub><\/mfrac><mo>,<\/mo><mo>&#160;<\/mo><mo>&#160;<\/mo><mo>&#160;<\/mo><mo>&#160;<\/mo><mo>&#160;<\/mo><mo>&#160;<\/mo><mi>n<\/mi><mo>&#8805;<\/mo><mn>1<\/mn><\/math>\r\n<\/p>\r\n<p>where \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><\/math>\r\n \u00a0is a positive constant.<br \/>\r\n(a) Write down expressions for\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>a<\/mi><mn>2<\/mn><\/msub><\/math>\r\n and \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>a<\/mi><mn>3<\/mn><\/msub><\/math>\r\n in terms of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><\/math>\r\n , giving your answers in their simplest form. (3 marks)<\/p>\r\n<p>Given that\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><munderover><mo>&#8721;<\/mo><mrow><mi>r<\/mi><mo>=<\/mo><mn>1<\/mn><\/mrow><mn>3<\/mn><\/munderover><msub><mi>a<\/mi><mi>r<\/mi><\/msub><mo>=<\/mo><mn>10<\/mn><\/math>\r\n <br \/>\r\n(b) find an exact value for \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><\/math>\r\n .\u00a0 (3 marks)<\/p>\r\n<div id=\"link17-link-503\" class=\"sh-link link17-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link17', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link17-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link17-content-503\" class=\"sh-content link17-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1828\" src=\"http:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-4.jpg\" alt=\"\" width=\"436\" height=\"841\" srcset=\"https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-4.jpg 436w, https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-4-156x300.jpg 156w\" sizes=\"auto, (max-width: 436px) 100vw, 436px\" \/><\/p>\r\n<p>\u00a0<\/div>\r\n<p>Q18. A company, which is making 140 bicycles each week, plans to increase its production.<br \/>\r\nThe number of bicycles produced is to be increased by d each week, starting from 140 in week 1, to 140 + d in week 2, to 140 + 2d in week 3 and so on, until the company is producing 206 in week 12.<br \/>\r\n(a) Find the value of d.\u00a0 (2 marks)<br \/>\r\nAfter week 12 the company plans to continue making 206 bicycles each week.<br \/>\r\n(b) Find the total number of bicycles that would be made in the first 52 weeks starting from and including week 1. (5 marks)<\/p>\r\n<div id=\"link18-link-503\" class=\"sh-link link18-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link18', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link18-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link18-content-503\" class=\"sh-content link18-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1831\" src=\"http:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-5.jpg\" alt=\"\" width=\"311\" height=\"698\" srcset=\"https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-5.jpg 311w, https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-5-134x300.jpg 134w\" sizes=\"auto, (max-width: 311px) 100vw, 311px\" \/><\/p>\r\n<p>\u00a0<\/div>\r\n<p>Q19. The first three terms of a geometric sequence are \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>7<\/mn><mi>k<\/mi><mo>&#160;<\/mo><mo>&#8211;<\/mo><mo>&#160;<\/mo><mn>5<\/mn><mo>,<\/mo><mo>&#160;<\/mo><mn>5<\/mn><mi>k<\/mi><mo>&#160;<\/mo><mo>&#8211;<\/mo><mo>&#160;<\/mo><mn>7<\/mn><mo>,<\/mo><mo>&#160;<\/mo><mn>2<\/mn><mi>k<\/mi><mo>&#160;<\/mo><mo>+<\/mo><mo>&#160;<\/mo><mn>10<\/mn><\/math>\r\n where\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><\/math>\r\n is a constant.<br \/>\r\n(a) Show that \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>11<\/mn><msup><mi>k<\/mi><mn>2<\/mn><\/msup><mo>&#160;<\/mo><mo>&#8211;<\/mo><mo>&#160;<\/mo><mn>130<\/mn><mi>k<\/mi><mo>&#160;<\/mo><mo>+<\/mo><mo>&#160;<\/mo><mn>99<\/mn><mo>&#160;<\/mo><mo>=<\/mo><mo>&#160;<\/mo><mn>0<\/mn><\/math>\r\n \u00a0 \u00a0(4 marks)<br \/>\r\nGiven that\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><\/math>\r\n is not an integer,<br \/>\r\n(b) show that\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><mo>=<\/mo><mfrac><mn>9<\/mn><mn>11<\/mn><\/mfrac><\/math>\r\n \u00a0 (2 marks)<br \/>\r\nFor this value of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>k<\/mi><\/math>\r\n ,<br \/>\r\n(c) (i) evaluate the fourth term of the sequence, giving your answer as an exact fraction,<br \/>\r\n(ii) evaluate the sum of the first ten terms of the sequence. (6 marks)<\/p>\r\n<div id=\"link19-link-503\" class=\"sh-link link19-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link19', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link19-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link19-content-503\" class=\"sh-content link19-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1834\" src=\"http:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-6.jpg\" alt=\"\" width=\"642\" height=\"604\" srcset=\"https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-6.jpg 642w, https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-6-300x282.jpg 300w\" sizes=\"auto, (max-width: 642px) 100vw, 642px\" \/><\/p>\r\n<p>\u00a0<\/div>\r\n<p>Q20. A sequence \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>u<\/mi><mn>1<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><msub><mi>u<\/mi><mn>2<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><msub><mi>u<\/mi><mn>3<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><\/math>\r\n is defined by \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>u<\/mi><mn>1<\/mn><\/msub><mo>=<\/mo><mn>7<\/mn><\/math>\r\n , \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>u<\/mi><mrow><mi>n<\/mi><mo>+<\/mo><mn>1<\/mn><\/mrow><\/msub><mo>=<\/mo><msub><mi>u<\/mi><mi>n<\/mi><\/msub><mo>+<\/mo><mn>15<\/mn><\/math>\r\n .<br \/>\r\nThe sum of the first\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n terms of this sequence is denoted by \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mi>n<\/mi><\/msub><\/math>\r\n . The terms of a second sequence \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>v<\/mi><mn>1<\/mn><\/msub><mo>&#160;<\/mo><mo>&#160;<\/mo><mo>,<\/mo><msub><mi>v<\/mi><mn>2<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><msub><mi>v<\/mi><mn>3<\/mn><\/msub><mo>&#160;<\/mo><mo>,<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><mo>.<\/mo><\/math>\r\n \u00a0form a geometric progression with first term 1.2 and common ratio 1.2.<br \/>\r\n(i) Show that \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>u<\/mi><mn>3<\/mn><\/msub><mo>&#160;<\/mo><mo>+<\/mo><mo>&#160;<\/mo><msub><mi>v<\/mi><mn>3<\/mn><\/msub><mo>&#160;<\/mo><mo>=<\/mo><mo>&#160;<\/mo><mn>38<\/mn><mo>.<\/mo><mn>728<\/mn><\/math>\r\n .\u00a0 [2 marks]<br \/>\r\n(ii) Show that \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mn>70<\/mn><\/msub><mo>&#160;<\/mo><mo>=<\/mo><mo>&#160;<\/mo><mn>36<\/mn><mo>&#160;<\/mo><mn>715<\/mn><\/math>\r\n .\u00a0 \u00a0 \u00a0 \u00a0 [3 marks]<br \/>\r\n(iii) Find the largest value of\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>p<\/mi><\/math>\r\n such that \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>v<\/mi><mi>p<\/mi><\/msub><mo>&#60;<\/mo><mo>&#160;<\/mo><msub><mi>S<\/mi><mn>70<\/mn><\/msub><\/math>\r\n .\u00a0 \u00a0 \u00a0[3 marks]<br \/>\r\n(iv) Find the largest value of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>q<\/mi><\/math>\r\n such that \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mi>q<\/mi><\/msub><mo>&#60;<\/mo><mo>&#160;<\/mo><msub><mi>v<\/mi><mn>70<\/mn><\/msub><\/math>\r\n .\u00a0 \u00a0 \u00a0 \u00a0[4 marks]<\/p>\r\n<div id=\"link20-link-503\" class=\"sh-link link20-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link20', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link20-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link20-content-503\" class=\"sh-content link20-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>&nbsp;<\/p>\r\n<p>\u00a0<\/div>\r\n<p>Q21. The first three terms of a sequence are given by\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>5<\/mn><mi>x<\/mi><mo>+<\/mo><mn>8<\/mn><mo>,<\/mo><mo>&#160;<\/mo><mo>&#8211;<\/mo><mn>2<\/mn><mi>x<\/mi><mo>+<\/mo><mn>1<\/mn><mo>,<\/mo><mo>&#160;<\/mo><mi>x<\/mi><mo>&#8211;<\/mo><mn>4<\/mn><\/math>\r\n <br \/>\r\n(a) When \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>x<\/mi><mo>=<\/mo><mn>11<\/mn><\/math>\r\n , show that the first three terms form the start of a geometric sequence, and state the value of the common ratio.<\/p>\r\n<p>(b) Given that the entire sequence is geometric for\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>x<\/mi><mo>=<\/mo><mn>11<\/mn><\/math>\r\n <br \/>\r\n\u00a0 \u00a0 \u00a0 \u00a0 (i) state why the associated series has a sum to infinity<br \/>\r\n\u00a0 \u00a0 \u00a0 \u00a0 (ii) calculate this sum to infinity.<\/p>\r\n<p>(c) There is a second value for\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>x<\/mi><\/math>\r\n that also gives a geometric sequence.<br \/>\r\nFor this second sequence<br \/>\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0(i) show that\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mi>x<\/mi><mn>2<\/mn><\/msup><mo>&#8211;<\/mo><mn>8<\/mn><mi>x<\/mi><mo>&#8211;<\/mo><mn>33<\/mn><mo>=<\/mo><mn>0<\/mn><\/math>\r\n <br \/>\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0(ii) find the first three terms<br \/>\r\n\u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0 \u00a0(iii) state the value of\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mrow><mn>2<\/mn><mi>n<\/mi><\/mrow><\/msub><\/math>\r\n and justify your answer.<\/p>\r\n<div id=\"link21-link-503\" class=\"sh-link link21-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link21', 503, 'Solution', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link21-toggle-503\">Solution<\/span><\/a><\/div><div id=\"link21-content-503\" class=\"sh-content link21-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone size-full wp-image-1892\" src=\"http:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1.png\" alt=\"\" width=\"332\" height=\"754\" srcset=\"https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1.png 332w, https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-132x300.png 132w\" sizes=\"auto, (max-width: 332px) 100vw, 332px\" \/><\/p>\r\n<p>\u00a0<\/div>\r\n<p>22. A geometric sequence has first term 80 and common ratio\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mfrac><mn>1<\/mn><mn>3<\/mn><\/mfrac><\/math>\r\n .<br \/>\r\n(a) For this sequence, calculate:<br \/>\r\n(i) the\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msup><mn>7<\/mn><mrow><mi>t<\/mi><mi>h<\/mi><\/mrow><\/msup><\/math>\r\n term;\u00a0 \u00a0 \u00a0 [2 marks]<br \/>\r\n(ii) the sum to infinity of the associated geometric series.\u00a0 \u00a0 [2 marks]<br \/>\r\nThe first term of this geometric sequence is equal to the first term of an arithmetic sequence.<br \/>\r\nThe sum of the first five terms of this arithmetic sequence is 240.<br \/>\r\n(b) (i) Find the common difference of this sequence.\u00a0 \u00a0 [2 marks]<br \/>\r\n(ii) Write down and simplify an expression for the nth term.\u00a0 \u00a0 [1 mark]<br \/>\r\nLet\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mi>n<\/mi><\/msub><\/math>\r\n represent the sum of the first\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n terms of this arithmetic sequence.<br \/>\r\n(c) Find the values of\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>n<\/mi><\/math>\r\n for which \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><msub><mi>S<\/mi><mi>n<\/mi><\/msub><mo>=<\/mo><mn>144<\/mn><\/math>\r\n .\u00a0 [3 marks]<\/p>\r\n<div id=\"link22-link-503\" class=\"sh-link link22-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link22', 503, 'Solution22', 'Hide Solution'); return false;\" aria-expanded=\"false\"><span id=\"link22-toggle-503\">Solution22<\/span><\/a><\/div><div id=\"link22-content-503\" class=\"sh-content link22-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p>(a)(i) 80\/729<\/p>\r\n<p>(ii)120<\/p>\r\n<p>(b)(i) -16\u00a0 (ii) 96 &#8211; 16n<\/p>\r\n<p>(c) 2, 9<\/p>\r\n<p>\u00a0<\/div>\r\n<p>23. (a) Three consecutive terms in an arithmetic sequence are\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>3<\/mn><msup><mi>e<\/mi><mrow><mo>&#8211;<\/mo><mi>p<\/mi><\/mrow><\/msup><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mn>5<\/mn><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mn>3<\/mn><msup><mi>e<\/mi><mi>p<\/mi><\/msup><\/math>\r\n . Find the possible values of \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mi>p<\/mi><\/math>\r\n . Give your answers in an exact form.<\/p>\r\n<p>(b) Prove that there is no possible value of q for which\u00a0 \r\n<math xmlns=\"http:\/\/www.w3.org\/1998\/Math\/MathML\"><mn>3<\/mn><msup><mi>e<\/mi><mrow><mo>&#8211;<\/mo><mi>q<\/mi><\/mrow><\/msup><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mn>5<\/mn><mo>&#160;<\/mo><mo>,<\/mo><mo>&#160;<\/mo><mn>3<\/mn><msup><mi>e<\/mi><mi>q<\/mi><\/msup><\/math>\r\n are consecutive terms of a geometric sequence.<\/p>\r\n<div id=\"link23-link-503\" class=\"sh-link link23-link sh-hide\"><a href=\"#\" onclick=\"showhide_toggle('link23', 503, 'Solution23', 'Hide Solution23'); return false;\" aria-expanded=\"false\"><span id=\"link23-toggle-503\">Solution23<\/span><\/a><\/div><div id=\"link23-content-503\" class=\"sh-content link23-content sh-hide\" style=\"display: none;\"><\/p>\r\n<p><img loading=\"lazy\" decoding=\"async\" class=\"alignnone wp-image-2105 size-large\" src=\"http:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-7-362x1024.jpg\" alt=\"\" width=\"362\" height=\"1024\" srcset=\"https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-7-362x1024.jpg 362w, https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-7-106x300.jpg 106w, https:\/\/ibalmaths.com\/wp-content\/uploads\/2020\/01\/1-7.jpg 441w\" sizes=\"auto, (max-width: 362px) 100vw, 362px\" \/><\/p>\r\n<p>\u00a0<\/div>\r\n<p>&nbsp;<\/p><!-- AddThis Advanced Settings generic via filter on the_content --><!-- AddThis Share Buttons generic via filter on the_content -->","protected":false},"excerpt":{"rendered":"Q1. Suppose &#945;,&#160;&#946; are the roots of x2+kx+1=0 and &#947;,&#160;&#948; are the roots of x2+x+k=0 . (a) if &#945;,&#160;&#946;,&#160;&#947;,&#160;&#948; are in arithmetic sequence, then find the common difference of this arithmetic sequence in terms of k , (b) if &#945;,&#160;&#946;,&#160;&#947;,&#160;&#948; are in geometric sequence, then find the common ratio of this geometric sequence in terms [&hellip;]<!-- AddThis Advanced Settings generic via filter on get_the_excerpt --><!-- AddThis Share Buttons generic via filter on get_the_excerpt -->","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","template":"","class_list":["post-503","knowledgebase","type-knowledgebase","status-publish","hentry","knowledgebase_cat-sequence-and-series","no-wpautop"],"_links":{"self":[{"href":"https:\/\/ibalmaths.com\/index.php\/wp-json\/wp\/v2\/knowledgebase\/503","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ibalmaths.com\/index.php\/wp-json\/wp\/v2\/knowledgebase"}],"about":[{"href":"https:\/\/ibalmaths.com\/index.php\/wp-json\/wp\/v2\/types\/knowledgebase"}],"author":[{"embeddable":true,"href":"https:\/\/ibalmaths.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/ibalmaths.com\/index.php\/wp-json\/wp\/v2\/comments?post=503"}],"version-history":[{"count":33,"href":"https:\/\/ibalmaths.com\/index.php\/wp-json\/wp\/v2\/knowledgebase\/503\/revisions"}],"predecessor-version":[{"id":953,"href":"https:\/\/ibalmaths.com\/index.php\/wp-json\/wp\/v2\/knowledgebase\/503\/revisions\/953"}],"wp:attachment":[{"href":"https:\/\/ibalmaths.com\/index.php\/wp-json\/wp\/v2\/media?parent=503"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}