Mathematics - Indefinite Integration Question with Solution | TestHub

Factor $f=\left(7{\tan }^{6}x-4{\tan }^{3}x\right){\sec }^{2}x$. With $t=\tan x,g=\int \left(7t^6-4t^3\right)dt=t^7-t^4+C$. From $g(0)=0,C=0$, and $g(\pi /4)=1-1=0$.