Question

f(x) = 3 cos(3ln(x))
find f'(x)

Answer 1

\[\eqalign{
&\frac{d}{dx}3\cos[3\ln(x)] \\
=&3\frac{d}{dx}\cos[3\ln(x)] \\
=&3\left[-\sin(3\ln x)\times3\times\frac{1}{x}\right] \\
=&-\frac{9\sin(3\ln x)}{x}}\]

Answer 2

thanks

Answer 3

No prob man!