Question

Integral question, please help

Answer 1

\[\int\limits t^3 \sqrt{t^2+1} \]

Answer 2

dt

Answer 3

Radicals... use a trigonometric substitution... specifically,
\[\Large t = \tan(x)\]

Answer 4

should I always use t = tan (x) for an integration problem like this?

Answer 5

the problem with integrals is that there is no straightforward way to answer them... you have to rely partly on experience. However, if you see the form
\[\Large \sqrt{t^2 + a^2}\] in your integral, always consider the trig-sub possibility
\[\Large t = a\tan(x)\]

Answer 6

thanks a bunch, I'll be posting another question in a few and would appreciate your help again.