(1) Notice all even powers. Use power-to-frequency conversion:

Plug in:

Simplify:


(2) Reduce power again for :

(This is derived from the power-to-frequency formula by changing ‘’ to ‘’ in that formula.)


(3) On the last term, swap even bunch:

Plug all in and obtain:


(4) Integrate the first three terms:


(5) Integrate the last term with -sub, setting and :


(6) Combine in final result:

Note: It is also possible to rewrite using trig identities. So, equally valid answers may look different than this.