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Integration by substitution crazy

Please please please can somebody show me how to solve this question please?
I know that the forum says do not give full solutions but i have been on this for an hour and it's driving me f***** crazy.
Thank you :smile:
9B5371AD-AC74-4336-B659-3B1F5B714D9D.jpeg
Reply 1
Original post by Rhys_M
Please please please can somebody show me how to solve this question please?
I know that the forum says do not give full solutions but i have been on this for an hour and it's driving me f***** crazy.
Thank you :smile:
9B5371AD-AC74-4336-B659-3B1F5B714D9D.jpeg

Try writing each factor in the integrand in terms of uu. When you find dudx\frac{du}{dx}, write this in terms of uu too. You should end up with a polynomial in uu as the integrand once you've removed all of the xxs.
(edited 3 years ago)
Reply 2
Well, find what du is..
You already know u = e^x - 1, therefore e^x + 1 must be..
Expand..
Integrate in the u world, and then substitute the u's back into the x world. (Don't forget the + C!)
Reply 3
It worked! Thanks so much.

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