Question 9.4.1.
We already know we can do the following problem using u-substitution, with
We see that is solved similarly, because
-
the exponent of
is odd. -
the exponent of
is odd. -
None of the above
Select the trigonometric identity needed to solve this problem.
Finally, put it all together to calculate
Hint.
The integral involves and where the exponent of is an odd, positive integer, namely, 3. So we factor out a copy of and use the identity to turn the remaining into an expression involving
This turns the integral into
which can be multiplied out, and then each part integrated by power rule.