# Thread: horizontal asymptotes

1. ## horizontal asymptotes

15x
____

(x^4 + 1)^(1/4)

i dont know what to do, do i divide each term by x^4 ? its what i did and i got the wrong answer unless i did it wrong

2. Originally Posted by wannous
15x
____

(x^4 + 1)^(1/4)

i dont know what to do, do i divide each term by x^4 ? its what i did and i got the wrong answer unless i did it wrong
To get a clearer relationship between numerator and denominator,
write the x part of the numerator to the power of 0.25

$\displaystyle \frac{15\left(x^4\right)^{\frac{1}{4}}}{\left(x^4+ 1\right)^{\frac{1}{4}}}$

$\displaystyle =15\left(\frac{x^4}{x^4+1}\right)^{\frac{1}{4}}$

now the limit as x approaches infinity is clearer.
Refer back to your original expression for the polarity as x goes to plus or minus infinity.

3. Originally Posted by wannous
15x
____

(x^4 + 1)^(1/4)

i dont know what to do, do i divide each term by x^4 ? its what i did and i got the wrong answer unless i did it wrong
... divide by $\displaystyle \textcolor{red}{x = (x^4)^{\frac{1}{4}}}$