How do you identify the vertical asymptotes of f(x) = (x+6)/(x^2-9x+18)?

1 Answer
Aug 10, 2015

I found:
x=6
x=3

Explanation:

You identify the vertical asymptotes by setting the denominator equal to zero: this allows you to see which x values the function cannot accept (they would make the denominator equal to zero).
So, set the denominator equal to zero:
x^2-9x+18=0 solve using the Quadratic Formula:
x_(1,2)=(9+-sqrt(81-72))/2=(9+-3)2 so you get:
x_1=6
x_2=3
So your function cannot accept these values for x;
The two vertical lines of equations:
x=6
x=3
will be your "forbidden" lines or vertical asymptotes.

Graphically:
enter image source here