Ask your own question, for FREE!
Mathematics 8 Online
OpenStudy (suwhitney):

Find the limit (if it exists)...

OpenStudy (suwhitney):

\[\lim_{x \rightarrow 2}\frac{ x-2 }{x^2+4x-12 }\]

OpenStudy (suwhitney):

I know the answer is 1/8 but I am not sure how to get it.. help is much appreciated

OpenStudy (johnweldon1993):

Well, if we just plug in 2, we get an indeterminant form... so we need to do some simplification first..looks like the denominator can be factored doesnt it :)

OpenStudy (suwhitney):

Yeah... like i keep getting 1/0 but I know thats not the answer, so its not as simple as just plugging it in right?

OpenStudy (perl):

try factoring the denominator

OpenStudy (johnweldon1993):

Correct, and in general (assuming this is precalc maybe?) whenever you get an indeterminant form of (0/0) you will need to simplify to continue. So lets factor the bottom of the fraction and see where that gets us

OpenStudy (suwhitney):

X^2+6x-2x-12=0 x(x+6)-2(x+6)=0 (x+6)(x-2)=0

OpenStudy (suwhitney):

is that right?

OpenStudy (johnweldon1993):

Correct! so...

OpenStudy (johnweldon1993):

Now we have \[\large \frac{(x - 2)}{(x + 6)(x - 2)}\] notice anything?

OpenStudy (suwhitney):

(2+6)(2-2) 8+0=8? 1/8?

OpenStudy (suwhitney):

Am i adding the bottom or multiplying?

OpenStudy (johnweldon1993):

we have an x - 2 on both ends of the fraction so... \[\large \frac{\cancel{(x - 2)}}{(x + 6)\cancel{(x - 2)}}\] which leaves us with \[\large \frac{1}{x + 6}\]

OpenStudy (suwhitney):

ohhhhhhhh!! hehee okay i see!! yay thank you so much!!

OpenStudy (johnweldon1993):

Haha there we go :) and anytime! Need anything else feel free to tag or message me :)

OpenStudy (suwhitney):

Okay, thank you so much! I am about to post one more question in a few minutes that I am having trouble with, I would love the help if you're able to. Thanks again!

OpenStudy (johnweldon1993):

Of course :)

Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!
Can't find your answer? Make a FREE account and ask your own questions, OR help others and earn volunteer hours!

Join our real-time social learning platform and learn together with your friends!