Practice Questions – Trigonometric Functions

Q1. The equation of a curve is $y=2 \cos x$ .
(i) Sketch the graph of  $y=2 \cos x$ for $–\mathrm{\pi }<\mathrm{x}<\mathrm{\pi }$ , stating the coordinates of the point of intersection with the y-axis. [2]

Points P and Q lie on the curve and have x-coordinates of $\frac{\pi }{3}$ and $\pi$ respectively.
(ii) Find the length of PQ correct to 1 decimal place. [2 marks]

The line through P and Q meets the x-axis at  $H\left(h,0\right)$ and the y-axis at  $K\left(0,k\right)$
(iii) Show that $h=\frac{5\pi }{9}$ and find the value of $k$ . [ 3 marks]