OK so when we're evaluating integrals of the form

we know reduction formulas from the past that make it simpler to evaluate them which is

however my problem is when the term inside the isn't just an x

In my case, it's

What do i do? I'm pretty sure it changes something because I'm off by a factor. My final answer is

However the correct answer is

I'm off by a factor of 5. Coincidence?