Thread: u substitution

I would like to evaluate this integral using u substitution, I tried

let u = sin x

but that did not seem to do anything, should I be changing the sec^2x - 1 to something else?



Any help is appreciated!

Do you know that: ??

Originally Posted by DarK

I would like to evaluate this integral using u substitution, I tried

let u = sin x

but that did not seem to do anything, should I be changing the sec^2x - 1 to something else?



Any help is appreciated!

In integrals like this the following substitution works 'almost always'...



Kind regards

sec(x)= 1/cos(x) so sec^2(x)= 1/cos^2(x). I presume you know how to "change" cos(x) into sin(x).

Let . That substitution kills the integral on one-go.