A calculus student is verifying the derivative formulas for trigonometric functions of uuu. Using the derivatives ddu(sinu)=cosu\displaystyle \frac{d}{du}(\sin u) = \cos udud(sinu)=cosu and ddu(cosu)=−sinu\displaystyle \frac{d}{du}(\cos u) = -\sin udud(cosu)=−sinu, help them prove that:
4 exam-style questions on Edexcel A Level Maths 9.6 Differentiating Trigonometric Functions. Each one has a worked solution and a mark scheme showing where the marks go.