Question

Given y = f(u) and u=g(x), find =f(g(x))g'(x) for the following functions.

dx
y = cos u, u = 4x - 3
dy
dx = f'(g(x))g'(x) = 0

Answer 1

-4sin(4x-3)

Explanation:

Given y = cos u, u = 4x - 3

dy/dx = dy/du * du/dx

dy/du = -sinu

du/dx = 4

dy/dx = -4sinu

since u = 4x - 3

dy/dx = -4sin(4x-3)