Recent content by anderma8
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Undergrad Solving Integral Problem: Stuck on Integration Steps, Need Suggestions
thanks for the 2nd set of eyes... Maybe it should read: 1/2 int (3u^-1) - (u^-2) du I end up with 1/2 u^-1 +c or 1/2(x^2 + 1) + c since u=x^2+1 -
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Undergrad Solving Integral Problem: Stuck on Integration Steps, Need Suggestions
I'm trying to do the following: int (3x^3 + 4x)/(x^2+1)^2 dx I let u = x^2+1 and I eventually get: int 3(u-1)+4/u^2 du/2 When I further break this down, I get: 1/2 int 3u^-1 -u^-2 du am I on the right track? When I integrate this, I'm thinking that I have to be doing something... -
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Undergrad Integrate (x^3 + 4x)/sqrt(x^2-4) dx
Never mind... I found my answer: (u+8)u^-1/2= u^1/2 + 8u^-1/2 Sorry about that! I forgot the parenthesis! -
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Undergrad Integrate (x^3 + 4x)/sqrt(x^2-4) dx
I'm trying to integrate the following: int (x^3 + 4x)/sqrt(x^2-4) dx I let u= x^2-4 so du/2 = xdx granted, the above also gives me x^2=u+4 so, this gives me: 1/2 int u+8 u^-1/2 du but the professor has: 1/2 int [u^1/2+8 u^-1/2] du Did I miss the first u^1/2 somewhere? where... -
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Graduate Help Needed: Understanding An=1x3x5... (2n-1)/(2n)^n Convergence
I'm trying to figure out the following: An=1x3x5... (2n-1)/(2n)^n and I'm trying to determine if it converges or diverges and if it converges, what the limit is. The answer is 1/2n x 3/2n x 5/2n... (2n-1)/2n and it converges, but I don't understand what they did or how they got to the... -
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Undergrad Infinite Series: sigma (2^n)+1/(2^n+1)
quasar987 & HallsofIvy, It's late where I am, but I wanted to thank you both. I am sure I am confusing several words in my posts and I'm not ashamed to admit it. That's at least how I learn! Thanks for the clarification. I have been looking at this stuff for quite a bit of time this... -
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Undergrad Infinite Series: sigma n^2/(n^2 +1)
If I take the limit on the sum... I get 1/1 = 1 If the limit does NOT = 0 then sigma f(x) diverges...I'm not quite sure I follow this... Does this mean that in order for the equation to converge, the sum (sigma) must be = to 0? -
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Undergrad Infinite Series: sigma (2^n)+1/(2^n+1)
robert Ihnot - Thanks for your input though! I guess I will need to substitute numbers to get the 1/2 and see that the other side goes to 0! Thanks! It's starting to make sense! -
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Undergrad Infinite Series: sigma (2^n)+1/(2^n+1)
(2^n)/(2^(n+1)) + 1/(2^(n+1)) This gives me 1/2 + 1/2^(n+1) which eventually goes to zero... :-) hence - my answer! -
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Undergrad Infinite Series: sigma (2^n)+1/(2^n+1)
i'm not quiet sure how to attack this problem: sigma (2^n)+1/(2^(n+1)) n->1 If I start plugging in #'s for n, then I get: n=1: 3/4 n=2: 5/8 n=3: 9/16... by this method, I see that it's going to 1/2, but I need another way to 'see' that. Any suggestions? -
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Graduate How can I integrate x^3 sin x without using integration by parts?
AKG - After we tried the problem over and over, when we got what we were expecting, you are exactly right! It was funny, when my team started this, we were apprehensive at best, but now we look at them and laugh 'cause they really are easy when you understand the problem! Thanks! -
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Graduate How can I integrate x^3 sin x without using integration by parts?
VietDao29 - THANKS! Your explanation is very clear and was exactly the insight my team needed. We ended up doing just what you suggested before reading your post. The good thing is that we feel confident that we did the project correctly and with your input, it validated our work! The... -
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Graduate How can I integrate x^3 sin x without using integration by parts?
we would but we can't use that as per the project instructions X-) Any suggestions? -
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Graduate How can I integrate x^3 sin x without using integration by parts?
but it's setting up the initial equation that is our road block. We get x^4e^x + dx but not clear on the setting up of X^3 cosx + dx -
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Graduate How can I integrate x^3 sin x without using integration by parts?
int x^3 cosx dx for this issue Thanks for the reply... essientially, we need to set this up and are having problems. We have an example of int x^4ex + dx. We get (Ax^4 + Bx^3 + Cx^2 + Ex +F) e^x + k. But we are stuck for finding the starting equation for int x^3 cosx.