Question

find limit: limit as x approaches infinity of (3+x)/(3-x)

Answer 1

The top approaches infinity, while the bottom also approaches infinity. Do you know L' Hopital's Rule yet?

Answer 2

no....

Answer 3

Ahh yes L'Hopital's rule would really help here...


first...do you know about derivatives yet?

Answer 4

nope i just started learning about limits

Answer 5

When you have an indeterminant form such as infinity/infinity, you can use that rule. But you would need to know about derivatives first, as johnweldon said.

Answer 6

ok....

Answer 7

Hang on I'm trying to remember how to do em without that rule :)...

Answer 8

Well we can always just use common sense here. Since the top approaches the inverse of the bottom, you can say that the answer is -1.

Answer 9

Hint: divide each piece by x

Answer 10

Oh yeah she probably knows that anything divided by infinity is 0, so we could do what jim said.

Answer 11

so the limit is 0?

Answer 12

So try that @BeautyQueen327 we can divide both the top and bottom by x, giving us:

(3/x+1)/(3/x-1)

Answer 13

3/x, when x approaches infinity, equals 0, because we are dividing by a huuuuge number. So you get (1/-1)=-1