I find your notation very difficult to read.
I'd use the product rule.
Let
then
Let
then
You should be able to proceed from here.
f(x)=(x^2)(√(1-x^2))
f'(x)=(2x)(√(1-x^2))+(x^2)(1/2)(√(1-x^2))^-1)(-2x)
f'(x)=(2x)((1-x^2)^1/2)+(x^2)(1/2)(√(1-x^2)^-1)(-2x)
f'(x)=√(4x^2-4x^4)+(1/2)(-2x^3)(1/(√(1-x^2))
umm i'm lost, i probably didn't even get the above right (sorry the format sucks pretty bad)
never mind i found a picture