Help on inverse trig differentiation

1. Nov 2, 2004

Simfish

Hi, I kow about the chain rule and such; but there I cannot solve a problem in my calc textbook.

y = Arctan(x^2-1) + Arccscx, x > 1.

Answer on back says 0; but my answer didn't go to 0. BTW, this is just one problem from a HW assignment so this shouldn't count as cheating.

Thanks!

-Simfish

Last edited: Nov 2, 2004
2. Nov 2, 2004

Tide

The derivative should be zero because

$$\tan^{-1} \sqrt{x^2-1} + \csc^{-1}x = \frac {\pi}{2}$$

3. Nov 2, 2004

arildno

Sleazy Tide!
Why didn't I see that..:grumpy:

4. Nov 2, 2004

Tide

LoL! Oh, you would have seen it - I just happened to see it first.