(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)
.