What is the Derivative of arcsec(sqrt(x))?

[gr3g1]

Hmmm, I don't seem to get it..

y' of arcsecx is : (1/x * sqrt(x^2 - 1))

im looking for arcsec(sqrt(x))

So I get (1/(sqrt(x)sqrt(x-1)) * 1/2sqrt(x))


Thats not the answer in the book :(

Help please

 

[Physics Monkey]

Your answer looks ok, what is the answer the book gives?

 

[gr3g1]

thanks for the reply!

The answer given is : 1 / (2x * sqrt(x-1))

 

[Physics Monkey]

Look closely, your answer is actually the same as the book's.

Edit: At least I think it is, unless I'm misinterpreting your answer.

 

[gr3g1]

Hmmm, I don't see it.. and i substitued X by a number, and it gives me 2 different answers

 

[Physics Monkey]

Is your answer $$\frac{1}{\sqrt{x}\sqrt{x - 1}}\frac{1}{2 \sqrt{x}}$$ or something else?

 

[gr3g1]

ya, that's my answer

 

[Physics Monkey]

Well, it is the same then. Just combine the two square roots of x to obtain
$$\frac{1}{\sqrt{x}\sqrt{x - 1}}\frac{1}{2 \sqrt{x}} = \frac{1}{2 x \sqrt{x - 1}}.$$

 

[gr3g1]

Ahh! Thanks so much!