How do you find horizontal and vertical asymptotes?

I know that for Horizontal I must find the left and right limits of infinity but I'm not sure about vertical asymptotes.

Question

How do you find horizontal and vertical asymptotes?

I know that for Horizontal I must find the left and right limits of infinity but I'm not sure about vertical asymptotes.

anonymous · Answer

for rational functions like $\large f(x)=\frac{g(x)}{h(x)} $, it's what makes g(x) = 0...

anonymous · Answer

*** sorry, h(x) = 0

richyw · Answer

alright well if you have a rational function. you get a vertical asymptote if the denominator is zero

richyw · Answer

or like what dpalnc said in a better way

richyw · Answer

so usually in elementary calculus you just have some polynomal, then you just gotta factor it and find the roots of the polynomial

richyw · Answer

or a trig function or something

anonymous · Answer

Ohh okay thanks for the help, I appreciate it. Also for the polynomial, when I find the roots , how are those included in my graph?

phi · Answer

if you have y = f(x)  
then the roots tell you were y=0
it is where the curve crosses the x-axis

anonymous · Answer

in addition to the rational function i mentioned, g(x) and h(x) must be relatively prime.....

anonymous · Answer

Oh I get it now, thanks a lot!