MCQ
If $\int {f(x)\,dx = f(x)} ,$ then ${\int {\left[ {f(x)} \right]} ^2}\,\,dx$ is
- ✓$\frac{1}{2}{\left[ {f\left( x \right)} \right]^2}$
- B${\left[ {f\left( x \right)} \right]^3}$
- C$\frac{{{{\left[ {f\left( x \right)} \right]}^3}}}{3}$
- D${\left[ {\,f\left( x \right)} \right]^2}$