9709 P32 - Nov 2023 - Q6
1879
(a) By sketching a suitable pair of graphs, show that the equation \(\cot x = 2 - \cos x\) has one root in the interval \(0 < x \leq \frac{1}{2}\pi\).
(b) Show by calculation that this root lies between 0.6 and 0.8.
(c) Use the iterative formula \(x_{n+1} = \arctan\left( \frac{1}{2 - \cos x_n} \right)\) to determine the root correct to 2 decimal places. Give the result of each iteration to 4 decimal places.
