Solving \int tan^{4}(x)dx Without a Table

[TromboneNerd]

how can i use u substitution to solve $$\int tan^{4}(x)dx$$?

I am not allowed to use a table, so i can't use the $$\int tan^{n}(u)du$$ formula. I have no work since i can't even make it fit $$\int udu$$. help?

 

[Cyosis]

Use the identity $1+\tan^2x=\sec^2x$.