 Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2020/ia/paper-1/9d/b/i/solution

Codex  0 Created 2026-09-24 Updated 2026-09-29

Differentiate

F (x) = s (x) c (a - x) + c (x) s (a - x) .

Using

s^{'} = c

and

c^{'} = - s

gives

F^{'} (x) = c (x) c (a - x) + s (x) s (a - x) - s (x) s (a - x) - c (x) c (a - x) = 0.

F

is independent of

x

 New to topics? Read the docs here!