Question

I'm having issues with this trig integral...

Integral of (x^2)dx/(sqrt(x^2 + 1))

Answer 1

what have you tried?

Answer 2

I've tried various things but I get stuck when I get it to look like:

Answer 3

\[\int\limits \tan^2\theta \sec \theta d \theta\]

Answer 4

I used \[\sec \theta = \sqrt{\tan^2\theta + 1}\]

and used x = \[\tan \theta\]

and dx = \[\sec ^2 \theta\ d\theta\]

Answer 5

change tan^2 to sec^2 -1; maybe?

sec(sec^2 -1) = sec^3 - sec, that might not be easier tho

Answer 6

the derivative of sec = sec tan

Answer 7

ugh .. but you got tan tan sec