The answer should be £6.70
Rather than carrying out IBP several times, let's establish a more general result. Let

One round of IBP, setting


gives


This is called a power-reduction formula. We could try solving for
explicitly, but no need.
is small enough to just expand
as much as we need to.





Finally,

so we end up with


and the antiderivative is

The answer is 0.079
*Remove percent sign
*Move decimal back 2 times
36/20
36:20
36 to 20
hope this helps