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:
263 exam-style questions on CCEA A Level Maths 3.5 Differentiation (A-level only), covering 3.5.1 Differentiation (A-level only), 3.5.2 Differentiation (A-level only), 3.5.3 Differentiation (A-level only), 3.5.4 Differentiation (A-level only), 3.5.5 Differentiation (A-level only), and 3.5 Differentiation (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.