# Math Help - finding horizontal asymptotes

1. ## finding horizontal asymptotes

Find the horizontal asymptote of arccot(x^2-x^4)

thanks so much!!

2. Originally Posted by henry5

Find the horizontal asymptote of arccot(x^2-x^4)

thanks so much!!
Horizontal Asymptotes occur when $f'(x)=0\text{ or }f'(0)$ is undefined.

$f'(x)=-\frac{2x-4x^3}{1+(x^2-x^4)^2}$

$f'(x)=0$ when $-2x+4x^3=0$. I leave it for you to find the values of x that cause this to be true.

I gave enough info to help get you through the problem. Try to finish this off.

--Chris

3. thanks for the reply

the x values that i get are +/- square root of 0.5 and 0.

the question though asks for the y values (like horizontal asymptote at y=2)

how would i find this?