# Derivative: arctan(sqrt((1-x)/(1+x)))

1. Jan 18, 2009

### cgrumiea

1. The problem statement, all variables and given/known data
Find the derivative:
arctan$$\sqrt{(1-x)/(1+x)}$$

2. Relevant equations
Chain Rule, Quotient Rule

3. The attempt at a solution
I've gotten to a point where I feel like I either don't know how to simplify from this point, or I've done something wrong:
[1/(1+((1-x)/(1+x)))] * [(-$$\sqrt{(1+x)}$$/2*$$\sqrt{1-x}$$)-($$\sqrt{1-x}$$/2*$$\sqrt{1+x}$$)]
1. The problem statement, all variables and given/known data

2. Relevant equations

3. The attempt at a solution

2. Jan 18, 2009

### Staff: Mentor

It looks about right (I didn't check that closely), but I don't understand some of what you have shown, namely the parts where it looks like you're dividing by 2.

Your derivative should look like this: