Although I want to support you kamil, given spec kids are competent this isn't as much a stretch as you make out your year 4 reference to be.
Farrrrkin funny tho 
imo it isn't bad if your doing it in a relaxed environment, I promote this kind of thing anyway as you might already know. But I don't agree, and find it actually hypocritical, that this is 'just another trivial thing you should be able to come up with in 2 seconds under pressure'.
Anyway if you wanna know, darkpheonix's question can be solved with more direct "vce techniques":
Yeah i was about to ask a similar question, how would i go about integrating: cos(6x))
(2cos^2(3x) -1))
then let
)
and the integrand turns into:
 du)
or some shit like that.