(a)
\The reduction formula is , where
is an integer.
Apply limits on each side to
.
.
(b)
\The definite integral is .
From part (a): .
In this case .
.
.
The definite integral is .
From part (a): .
In this case .
Substitute.
.
.
(c) show that .
Consider .
Substitute .
From part (a): .
Substitute .
.
.
(a) .
(b) and
.
(c) .