If ∫((1-5 cos^2 x)/(sin^5 x cos^2 x)) d x=f(x)+ C, where C is the constant of integration, then f((π)/6)-f((π)/4) is equal to

If $\displaystyle \int\left(\frac{1-5 \cos ^2 x}{\sin ^5 x \cos ^2 x}\right) d x=f(x)+\mathrm{C}$, where C is the constant of integration, then $\displaystyle f\left(\frac{\pi}{6}\right)-f\left(\frac{\pi}{4}\right)$ is equal to