SOLUTION: What are the horizontal and vertical asymptotes of the rational function (-3x+5)/(15x^2+2x-1)?

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Question 726562: What are the horizontal and vertical asymptotes of the rational function (-3x+5)/(15x^2+2x-1)?
Found 2 solutions by lynnlo, jsmallt9:
Answer by lynnlo(4176) About Me  (Show Source):
You can put this solution on YOUR website!
HORIZONTAL=========================±∞
VERTICAL============±∞,-1/3

Answer by jsmallt9(3759) About Me  (Show Source):
You can put this solution on YOUR website!
%28-3x%2B5%29%2F%2815x%5E2%2B2x-1%29
The vertical asymptotes will occur for x values that make the denominator zero (and are not "holes"). To find them, factor the numerator and denominator:
%281%2A%28-3x%2B5%29%29%2F%28%285x-1%29%283x%2B1%29%29
If there was a common factor between the numerator and denominator, then there would be a "hole". We do not have a common factor so there are no holes. Now we can proceed to determine the vertical asymptotes. We set the denominator equal to zero:
(5x-1)(3x+1) = 0
and solve for x. From the Zero Product Property:
5x-1 = 0 or 3x+1 = 0
Solving we get:
x = 1/5 or x = -1/3
These are the equations for the vertical asymptotes.

For the horizontal asymptotes, we start with the original function:
%28-3x%2B5%29%2F%2815x%5E2%2B2x-1%29
and divide each term by the highest power of x. This would be x%5E2:
%28-3%2Fx%2B5%2Fx%5E2%29%2F%2815%2B2%2Fx-1%2Fx%5E2%29
Now we look at this and figure out what happens when x becomes larger and larger (both positively and negatively). As x becomes large each of those fractions (which have an x in the denominator and a constant in the numerator) will become smaller and smaller. IOW: closer and closer to zero. So the numerator will become close to zero the the denominator will become close to 15. 0/15 is zero so the horizontal asymptote is y = 0.

FWIW: Here's what the graph looks like:
graph%28500%2C+500%2C+-5%2C+5%2C+-10%2C+10%2C+%28-3x%2B5%29%2F%2815x%5E2%2B2x-1%29%29