## Search found 14 matches

Tue Sep 15, 2009 7:01 am UTC
Forum: Mathematics
Topic: The limit of a product is the product of the limits proof.
Replies: 1
Views: 819

### The limit of a product is the product of the limits proof.

Need help verifying if this proof is correct the way I have it stated. Prove if lim_{x\to a}f(x) = L and lim_{x\to a}g(x) = M then lim_{x\to a}f(x)g(x) = LM . Proof: Let \epsilon > 0 be given. \begin{align*} &|f(x)g(x) - LM| \\ = &|f(x)...
Sat Sep 12, 2009 12:48 am UTC
Forum: Mathematics
Topic: There's some way to calculate this, right?
Replies: 6
Views: 2143

### Re: There's some way to calculate this, right?

Combinations should be covered at least in Pre Calculus. I don't recall messing with it in first semester Calculus, but in second semester it cropped up again. However, by that time they expect you to be able to do it without thinking very much.
Thu May 28, 2009 9:17 pm UTC
Forum: Mathematics
Topic: Integrals trig substituation
Replies: 4
Views: 726

### Re: Integrals trig substituation

[imath]dx = \cos\theta\, d\theta[/imath]

Cool I worked it all out and that works perfectly now. =)

For the limits, usually I drop the limits while doing the substitution then at the end substitute x back in and use the original limits.

Thanks for the help.
Thu May 28, 2009 8:59 pm UTC
Forum: Mathematics
Topic: Integrals trig substituation
Replies: 4
Views: 726

### Integrals trig substituation

I am having trouble with a concept in calculus called trigonometic substitution. Here is a problem. \int_{0}^{1} \sqrt{1 - x^2}\, dx By the picture this is a half circle with radius 1. I am integrating on the interval [0,1] so it should give me the area of quarter of a circle. Since this is the unit...
Thu Apr 16, 2009 7:14 pm UTC
Forum: Computer Science
Topic: Level of Math/CS for Art of Computer Programming?
Replies: 7
Views: 2885

### Re: Level of Math/CS for Art of Computer Programming?

Thanks for your input. Ultimatily I am not sure what I want to do with my education, but I'm not so sure I want to just be a programmer. I am more interested in how this stuff works as oppose to making it work. Right now I an majoring in mathematics, though I have taken a few cs classes. I was consi...
Wed Apr 15, 2009 1:50 am UTC
Forum: Computer Science
Topic: Level of Math/CS for Art of Computer Programming?
Replies: 7
Views: 2885

### Level of Math/CS for Art of Computer Programming?

At what level of math and computer science understanding can I expect to be able to pick up and read Art of Computer Programming and understand it? I am a first semester calc student and I have a basic idea of what discrete math is. I am also taking a class called theories of computation, which cove...
Wed Feb 18, 2009 9:57 am UTC
Forum: Mathematics
Topic: Proving Limits don't exist
Replies: 22
Views: 3382

### Re: Proving Limits don't exist

\begin{align*} \lim_{x\to 2} \frac{x^2-x+6}{x-2} &= \frac{2^2 - 2 + 6}{0}\\ &= \frac{8}{0} \end{align*}

My professor said just to say that any constant over 0 means that the limit is undefined. and [imath]\frac{0}{0}[/imath] = more work.

Was mainly looking to comprehend that concept a little more.
Wed Feb 18, 2009 12:31 am UTC
Forum: Mathematics
Topic: Proving Limits don't exist
Replies: 22
Views: 3382

### Re: Proving Limits don't exist

Cool, from what I have read in here I came up with this. Which seems mostly correct. I use DNE for does not exist. Is there a better notation for that? Anyway, thanks for the help. Original problem \lim_{x\to 2} \frac{x^2 - x + 6}{x - 2} Break down problem into seperate functions \begin{align*}f(...
Tue Feb 17, 2009 4:58 pm UTC
Forum: Mathematics
Topic: Proving Limits don't exist
Replies: 22
Views: 3382

### Re: Proving Limits don't exist

I have seen it on a couple forums and what not. I really didn't understand it, but I am assuming that will probably be revealed to me soon.
Tue Feb 17, 2009 8:43 am UTC
Forum: Mathematics
Topic: Proving Limits don't exist
Replies: 22
Views: 3382

### Re: Proving Limits don't exist

Yeah, I have seen the epsilon-delta thing. I pretty much understand it now. Thanks for your help.
Tue Feb 17, 2009 8:10 am UTC
Forum: Mathematics
Topic: Proving Limits don't exist
Replies: 22
Views: 3382

### Re: Proving Limits don't exist

Yeah, I see how it is doing it. Because the numerator is always positive, so if the bottom is just a little below 2 the entire fraction is negative. And as it gets closer to 2 it get infinitely negative and if it is just a little bigger it stay positive and gets infinitely positive. Is there a way t...
Tue Feb 17, 2009 7:22 am UTC
Forum: Mathematics
Topic: Proving Limits don't exist
Replies: 22
Views: 3382

### Proving Limits don't exist

I am taking a calculus 1 class and I am having trouble understanding a concept dealing with limits. Take this problem \lim_{x\rightarrow2}\frac{x^2+x-6}{x-2} I can find that the limit is 5 by factoring the top and canceling the (x - 2). I have no idea how to work that out with limit laws though. My ...
Wed Apr 02, 2008 4:20 am UTC
Forum: School
Topic: What college did YOU go to?
Replies: 42
Views: 4466

### Re: What college did YOU go to?

I go to Orange Coast College (Community College) =( Hopefully soon I will get into a real college.
Tue Apr 01, 2008 11:17 pm UTC
Forum: Computer Science
Topic: Resources for learning the Math and Science behind computing
Replies: 45
Views: 98912

### Re: Possibly a very stupid question

MIT's open courseware has CS courses available here: http://ocw.mit.edu/OcwWeb/Electrical-Engineering-and-Computer-Science/index.htm if any of those topics appeal to you. Wow, I have gone to their open courseware before and it didn't seem like there was much there. I must of been in the wrong area ...