Lim as x approaches a of (x^2-a^2) / (x^4-a^4)
Favorites|Homepage
Subscriptions | sitemap
HOME > > Lim as x approaches a of (x^2-a^2) / (x^4-a^4)

Lim as x approaches a of (x^2-a^2) / (x^4-a^4)

[From: ] [author: ] [Date: 12-04-27] [Hit: ]
The top (x^2 - a^2) cancels out the bottom (x^2 - a^2) leaving you with 1 on top.Now you are left with 1/( x^2 + a^2).Since the bottom cannot be factored any further, you now plug in a for x to solve.This gives you: 1/(a^2 + a^2) = 1/2a^2-This is probably going to be a really bad answer;however I cant but notice1/2 a because those two things are kinda half of each other xD 4 and 2. x^2 and x^4.......
This is a problem from the 1998 Calculus AB released AP exam and I don't get it.
Answer choices:
A) 1/a^2
B) 1/2a^2
C) 1/6a^2
D) 0
E) nonexistent

The answer is B but like I said, I don't understand how one gets B.

-
the bottom part is a difference of a quad, which fators out to: (x^2 - a^2)(x^2 + a^2).
The top (x^2 - a^2) cancels out the bottom (x^2 - a^2) leaving you with 1 on top.
Now you are left with 1/( x^2 + a^2). Since the bottom cannot be factored any further, you now plug in "a" for "x" to solve. This gives you: 1/(a^2 + a^2) = 1/2a^2

-
This is probably going to be a really bad answer;however I can't but notice 1/2 a because those two things are kinda half of each other xD 4 and 2. x^2 and x^4. Yeah, I'm bored so just go with some person who posts some really hard logic stuff o -o This is going to get down-voted.
1
keywords: Lim,approaches,as,of,Lim as x approaches a of (x^2-a^2) / (x^4-a^4)
New
Hot
© 2008-2010 http://www.science-mathematics.com . Program by zplan cms. Theme by wukong .