 Solution

ID: past-exam-of-the-mathematics-course-of-the-year-1-of-the-natural-sciences-course-of-the-university-of-cambridge/2007/paper-1/section-a/2/a/solution

The chain rule for the cosine gives

\frac{d}{d x} cos (5 x) = - 5 sin (5 x) .

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