Given y = f(u) and u=g(x), find =f(g(x))g'(x) for the following functions.dxy = cos u, u = 4x - 3dydx = f'(g(x))g'(x) = 0

Answer:
[tex]\frac{dy}{dx}=4\sin (4x-3)[/tex]Explanation:
Given the following functions:
[tex]\begin{gathered} y=\cos u \\ u=4x-3 \end{gathered}[/tex]We find the derivative below:
[tex]\begin{gathered} \frac{dy}{dx}=f^{\prime}\lbrack g(x)\rbrack g^{\prime}(x) \\ Since\text{ u=g(x)} \\ \frac{dy}{dx}=f^{\prime}\lbrack u\rbrack u^{\prime} \end{gathered}[/tex]Since y=f(u)
[tex]\begin{gathered} \frac{dy}{dx}=\frac{dy}{du}\times\frac{du}{dx} \\ =\sin u\times4 \\ =4\sin u \end{gathered}[/tex]Substitute u=4x-3 into dy/dx:
[tex]\frac{dy}{dx}=4\sin (4x-3)[/tex]