## anonymous 5 years ago why is this -infinity

1. anonymous

(x+7)/(x^2-4) limit approaches 2 negatively between -2 and 2 the denominator is negative but once it passes -2 it becomes +infinity so shouldn't it be +infinity instead of -infinity?

2. NickS

If you haven't already, graph the equation on your graphing calculator. As you'll notice, if the limit is appoaching -2 from the left, then the answer will be positive infinity. However, if the limit is approaching -2 from right, then the answer will be -infinity.

3. anonymous

so then instead of looking at the direction of y, I would look at the direction of x?

4. NickS

Does the limit in the problem look something like this? $\lim_{n \rightarrow -2^+}$

5. anonymous

$g(x)=x+7/x ^{2}-4$ $\lim_{x \rightarrow 2^-} g(x)$

6. NickS

All right, see how there is a "-" sign above the 2? The negative sign means that the limit is approaching 2 from the left side. If there was a "+" sign above the 2, then the limit would be apporaching 2 from the right side. So, yes, it's how you look at from the direction of x.

7. anonymous

Alright, I getting to understand it, thanks!!

8. NickS

No problem, I'm glad I could help.