Please answer those 2 questions

D Question 15 Find the indicated derivative. Find y(4) if y = -9 cos x. O y(4) = 9 cos x O y(4) = 9 sin x O y(4) = -9 cos x O y(4) = -9 sin x D Question 16 Provide an appropriate response. If xy2 = 4 and dx/dt = -5, then what is dy/dt when x = 4 and y = 1? O O 00 / 07 O O