Integration by Substitution : More Problems (part 2)

[WatchMath]

Thank you for even comparing my video with Sal's video. Could you point me which video that you mention? I only see the one that Sal discuss the u-substitution method when the choice of u is very obvious like for the sin x/(cos x)^2 problem. He didn't discuss a more difficult problem that I discussed in this and the third video.

[bhmessarosh]

its pretty obvious that khan does this quite a bit better