Nếu \(\int {f\left( x \right)} dx = \dfrac{{{x^3}}...

Câu hỏi: Nếu \(\int {f\left( x \right)} dx = \dfrac{{{x^3}}}{3} + {e^x} + C\) thì \(f\left( x \right)\) bằng 

A

\(f\left( x \right) = 3{x^2} + {e^x}\).

B \(f\left( x \right) = \dfrac{{{x^4}}}{3} + {e^x}\).

C \(f\left( x \right) = {x^2} + {e^x}\).    

D \(f\left( x \right) = \dfrac{{{x^4}}}{{12}} + {e^x}\).