# Differentiation

• Oct 1st 2009, 05:11 PM
Morgan82
Differentiation
I need to find the derivative of this..

y = inverse sin of (sqrt(1-x^2))

I got an answer, and in the denominator, I got sqrt(-x^2).

This is undefined. Whats going on??
• Oct 1st 2009, 05:28 PM
VonNemo19
Quote:

Originally Posted by Morgan82
I need to find the derivative of this..

y = inverse sin of (sqrt(1-x^2))

I got an answer, and in the denominator, I got sqrt(-x^2).

This is undefined. Whats going on??

Remember

$\frac{d}{dx}\left[\arcsin(u)\right]=\frac{u'}{\sqrt{1-u^2}}du$

In your case... $u=\sqrt{1-x^2}$
• Oct 2nd 2009, 12:47 AM
mr fantastic
Quote:

Originally Posted by Morgan82
I need to find the derivative of this..

y = inverse sin of (sqrt(1-x^2))

I got an answer, and in the denominator, I got sqrt(-x^2).

This is undefined. Whats going on??

What's going on is that you made a mistake. 1 - (1 - x^2) = x^2 NOT -x^2.