# Limit help please

• May 19th 2009, 06:30 PM
ItsAndroo
Can someone please give answers to these questions and explanations please?
As well as any creative ideas to present it?
lol i have a calculus project on this and need to present it to my pre-cal class.
I have the basic concept down, but not really in depth.
Thanks, any help is greatly appreciated!

What does a limit of a graph as it approaches infinity tell you about the graph?
and
How do you find the limit of functions as they approach infinity?
• May 19th 2009, 06:46 PM
VonNemo19
Could you please give me an example of what you mean. I'm not quite sure that I understand your question.

If what you mean is that the behavior of the graph tends to infinity as x tends to a nuber c, we say that $\lim_{x\to{c}}f(x)=DNE$ (does not exist), because thedefinition of limit states that a function f(x) has a limit as x tends to c only if, as x tends to c, f(x) tends to some number L.

Does that help?
• May 19th 2009, 07:13 PM
VonNemo19
If $f(x)\to{\infty}$ as $x\to{c}$ then the line $x=c$ is a vertical asymptote of the graph $y=f(x)$.

Is that what your asking? That's 'something that can be said about the graph'.
• May 19th 2009, 07:17 PM
ItsAndroo
I'm not sure, lol.
I'm still trying to learn all of the material, i've never dealt with calculus, we're doing this project as an intro to calculus.
But i found the answer for my first question to be "The limit of the graph as it approaches infinity tells you if it has a horizontal asymptote and what the end behavior model would look like. and my teacher said it was correct.
I don't really understand that question either.
Hope that helps.
And thank you for taking your time to help me.
• May 19th 2009, 07:22 PM
derfleurer
The limit of f(x) as x approaches infinity has no bearing on a horizontal asymptote. Something as simple as x^2 is a perfect example where that information is useless.

The idea of a limit is to find out what value you're approaching, rather than what value actually exists. For example, the limit of $\frac{(x+2)(x-3)}{(x+2)}$ as x approaches -2 is -5. Despite the fact that plugging in -2 yields 0/0.
• May 20th 2009, 01:54 PM
ItsAndroo
Alright, thank you to everyone for the help.
But now does anyone have any creative ideas to present my project on a power point?
Themes, methods, etc.
Anything that will contribute to it's effectiveness in teaching and in creativity.