Question

Find derivative

Answer 1

\[x \sqrt{1-x^2}+arccosx\]

Answer 2

I ended up with

\[\sqrt{1-x^2}+\frac{ x }{ 2\sqrt{1-x^2} }*-2x-\frac{ 1 }{ \sqrt{1-x^2} }\]

Answer 3

Answer does not need to be simplified

Answer 4

yup looks correct :) good job.

Answer 5

Ok. I got no points for that on my test. Thanks

Answer 6

Hmm that's strange.

Here is the confirmed solution:
http://www.wolframalpha.com/input/?i=derivative+x+sqrt%281-x%5E2%29%2Barccos+x

If you click the little "step-by-step solution" button, near the bottom you will find the un-simplified solution. And it matches what you have.