1. ## integral question

Hello. I have difficulty solving the question int (sqrt(1-x^2)) dx using u=arcsinx. Any ideas would be greatly appreciated. all i was able to do is rewrite it as int (1-x^2)/(sqrt(1-x^2)) dx but im not too sure what to do after this.

BTW you need to use u=arcsinx so please don't post solutions doing otherwise.

2. $
u=arcsinx
$

$
sinu=x
$

$
dx=cosu \: du
$

$
\int \sqrt{1-x^2} \: dx= \int \sqrt{1-sin^2 u} \: cos u du=\int cos^2 u \: du
$