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Can someone help me solve this using substitution please?

I tried to get the detailed solution from Wolfram Alpha: http://www.wolframalpha.com/input/?i=integral+((tanx)^3)

but, it uses the "reduction formula" which is something I have not learned yet not to mention that this question is in the "substitution" section of my text book.

I was just hoping somebody could solve this for me using substitution because when I let u = tanθ, I get stuck and I can't see what else to do.

Any help would be GREATLY appreciated!

Thanks in advance!

P.S.

If you want to see my work, it is attached. This particular problem is the last one of the PDF and is #47.