Integration by parts

1. Jul 23, 2003

iceman

Hi can anyone help me solve this integral, I'm having trouble with this one???

the integral is: int(sin^{8}x.dx)->upper limit=pi ->lower limit=0.

Q) Evaluate the integral exactly using integration by parts to get a reduction formulae for int(sin^{n}x.dx)

2. Jul 23, 2003

KLscilevothma

Hint(to find the reduction formula):
[inte]0pi sinnx dx
= - [inte]0pi sinn-1x d (cos x)
= [- cos x sinn-1x]0pi + [inte]0pi cos x d(sinn-1x)
= [inte]0pi cos x d(sinn-1x)
= ...