question_answer

If \[f(x)\] and \[g(x)\] are two functions with\[g(x)=x-\frac{1}{x}\] and \[fog(x)={{x}^{3}}-\frac{1}{{{x}^{3}}}\], then \[f(x)\] is:

A)  \[3{{x}^{2}}+3\]                              

B)  \[{{x}^{2}}-\frac{1}{{{x}^{2}}}\]

C)  \[1+\frac{1}{{{x}^{2}}}\]                              

D)  \[3{{x}^{2}}+\frac{3}{{{x}^{4}}}\]