# Math Help - Stuck on an integral!

1. ## Stuck on an integral!

$\int \sqrt(6x-x^2)$

I don't know how to go about this one!
Lately we have been looking at integration with partial fractions, and integration using trig replacment but I can't see either working! Advice?
*the whole equation is under the square root*

- Thank You

2. $6x-x^2=-(x^2-6x)=9-(x^2-6x+9)=9-(x-3)^2,$ then put $x-3=3\sin\varphi.$

3. Brilliant ty ty!!