The function is
and the inerval is
.
Average value of the function
on
is defined as
.
Here
.
Average value of
is
.

Consider
.
Differentiate on each side with respect to
.

.
Change of integral limits:
\Lower limit: If
then
.
Upper limit: If
then
.
Substitute
,
and change of integral limits in
.

.
Average value of the function
on
is
.
Average value of the function
on
is
.