Nếu \(\int {f\left( x \right){\rm{d}}x}  = \frac{1...

Câu hỏi: Nếu \(\int {f\left( x \right){\rm{d}}x}  = \frac{1}{x} + \ln \left| {2x} \right| + C\) với \(x \in \left( {0; + \infty } \right)\)thì hàm số \(f\left( x \right)\) là

A \(f\left( x \right) =  - \frac{1}{{{x^2}}} + \frac{1}{x}.\)   

B  \(f\left( x \right) = \sqrt x  + \frac{1}{{2x}}.\)          

C \(f\left( x \right) = \frac{1}{{{x^2}}} + \ln \left( {2x} \right).\)  

D \(f\left( x \right) =  - \frac{1}{{{x^2}}} + \frac{1}{{2x}}.\)