Hoe do you differentiate f(x)=ln(e^(4x)+3x) ?

1 Answer
Nov 9, 2015

f'(x)=frac{4e^{4x}+3}{e^{4x}+3x}

Explanation:

Let u=e^{4x}+3x.

frac{du}{dx}=4e^{4x}+3

f'(x)=frac{d}{dx}[ln(e^{4x}+3x)]

=frac{d}{dx}[ln(u)]

=frac{d}{du}[ln(u)]frac{du}{dx}

=(1/u)(4e^{4x}+3)

=frac{4e^{4x}+3}{e^{4x}+3x}