Another derivatives of inverse trig function

I need help taking the derivative of y = arcsec(2x^2)

This is what I do

y = arcsec(2x^2)

x=sec(2x^2)

y'=-4ysin(2y^2)

I am suppose to get a polynomial but I cannot take the derivative of it to get one. I just get stuck at the last step. Any help? This seems not to make any sense at all for me (Headbang)

Re: Another derivatives of inverse trig function

Re: Another derivatives of inverse trig function

Quote:

Originally Posted by

**Quacky**

with that I get

From here I do not know where to go.

Re: Another derivatives of inverse trig function

Re: Another derivatives of inverse trig function

Thanks, I had you third last step and see sec^2y and I was all like "what do I do? Help someone!". Thanks for pointing out the unit trig identity. It was much easier than it appeared :)

Re: Another derivatives of inverse trig function

Quote:

Originally Posted by

**Barthayn** Thanks, I had you third last step and see sec^2y and I was all like "what do I do? Help someone!". Thanks for pointing out the unit trig identity. It was much easier than it appeared :)

Isn't this always the case?(Wink)