Reverse chain problem doesn’t make sense

I’ve been set a reverse chain problem to integrate:

sec^2(x) (1+tan^2(x))

And I’m completely stuck, the solution bank isn’t helping either!
I would be really grateful for any help!

Reply 1

mqb2766

Original post by Chinook7532

I’ve been set a reverse chain problem to integrate:

sec^2(x) (1+tan^2(x))

And I’m completely stuck, the solution bank isn’t helping either!
I would be really grateful for any help!

A substitution of u=tan(x) would probably be the safest way to go, though you could expand the brackets and do reverse chain on each (well the second) term (basically the same as substitution). Once you have the answer, its possible to see how you could do reverse chain in the first place, but ...