Câu 14:
Cho ∫01f(4x)dx=4\int\limits_0^1 {f\left( {4x} \right)} dx = 40∫1f(4x)dx=4. Tính I=∫04f(x)dxI = \int\limits_0^4 {f\left( x \right)} dxI=0∫4f(x)dx.
