(1) Trig substitution. Notice , so we should make use of the identity .

Pick and thus .

Then:

Plug in:

(We assume that for the relevant values of .)


(2) Perform integration.

Either recall from memory, or multiply above and below by , and obtain:


(3) To convert to we need given that .

Draw triangle expressing :

center

Therefore . We already know . Thus:


(4) Simplify with log rules: