an interesting integral

[@MASHabibi-d2d]

Thanks for an other video master

[@ahmedsabri-ng2xx]

an interesting integral

[@maxvangulik1988]

I=int((xsec^2(x)+tan(x))/(1+xtan(x))^2)dx
t=1+xtan(x)
dt=(xsec^2(x)+tan(x))dx
I=int(t^-2)dt
I=-1/t+C
I=-cos(x)/(cos(x)+xsin(x))+C

[@maxvangulik1988]

bro changed the problem on step 3 for no reason