Question

Найдите f"(x) и f"(3/5), если f(x)=3lnx

Answer 1

$f(x)=3ln x;\\f'(x)=(3ln x)'=3(ln x)'=3*frac{1}{x}=frac{3}{x};\\f'(frac{3}{5})=frac{3}{frac{3}{5}}=5;$