If ∫(1-5cos2xsin5x cos2x)dx=f(x)+C, where C is the constant of integration, then f(π6)-f(π4) is equal to [2026]
(1)
∫dxsin5xcos2x-5∫dxsin5x
=∫sec2x dxsin5x-5∫dxsin5x
By IBP
=tanxsin5x-∫5sin6xcosxtanx dx-5∫dxsin5x
=tanxsin5x+C
f(x)=tanxsin5x
f(π6)-f(π4)=253-(2)5=42-323
=323-42
=43(8-6)