Recent content by SumThePrimes
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Graduate Indefinite Integral for -.5*(ln(2))^2
It is (e^x)+1 . I tried using limits on the bounds and then integration by parts and then switching certain values to other limited integrals and canceling... I tell you what that didn't work. I also tried a limit for the natural logarithm with an integral for the Dirichlet eta function, but...- SumThePrimes
- Post #4
- Forum: Calculus
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Graduate Indefinite Integral for -.5*(ln(2))^2
Hello, I have recently encountered an integral that I have been able to evaluate in a sick, unholy way, and for making a proof much more elegant I would like a simple way to evaluate the integral from 0 to infinity of ln(x)/(e^x+1) . thank you!- SumThePrimes
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- Indefinite Indefinite integral Integral
- Replies: 3
- Forum: Calculus
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Undergrad Sum of series- Fibonacci numerator, geometric denominator
If f(x)=1+1x+2x^2+3x^3+5x^4+8x^5... f(x)*x=1x+1x^2+2x^3+3x^4+5x^5... f(x)*x^2 =1x^2+1x^3+2x^4+3x^5... Then f(x)-x*f(x)-x^2*f(x)=1 , so f(x)(1-x-x^2)=1 , so f(x)=1/(1-x-x^2) Your series is this function evaluated at x=1/2 , which has a value of 4. Isn't that something? :)- SumThePrimes
- Post #7
- Forum: Calculus
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Graduate Solving the Limit of sin(\pi*n/4)*\Gamma(x) Problem
I've recently been confronted with the limit as n goes to 0 of sin(\pi*n/4)*\Gamma(x) , and have no idea on how to confront the problem, as I have little familiarity with the gamma function. Is there any relatively easy ways to prove this, or at least ways that use methods not difficult to...- SumThePrimes
- Thread
- Interesting Limit
- Replies: 3
- Forum: Calculus
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Undergrad F(a+b)=f(a)*f(b) and f(a*b)=f(a+b)
For one that satisfies only the second statement, if f(a+b)=f(a*b), then f(a+0)=f(a*0), so f(a) is f(0) for any a, so the second statement alone assures us that this function is constant, but there is no way to know what constant with only the fact f(a+b)=f(a*b) . Now combine your second...- SumThePrimes
- Post #6
- Forum: Calculus
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Graduate This bigger than grahams number?
When I said your number I was referring to the original posts number, not necessarily your clarification of it. I thought I knew the syntax with these towers, I know tetration starts at the top, it probably is best to use grouping symbols, as you say. Although I am rather sure in general you...- SumThePrimes
- Post #6
- Forum: Linear and Abstract Algebra
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Graduate This bigger than grahams number?
I always though with exponent towers you start at the top, not the bottom, I'm rather sure that's how you work with those... Regardless, your number is less than Grahams number.- SumThePrimes
- Post #4
- Forum: Linear and Abstract Algebra
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Graduate This bigger than grahams number?
Do you mean is (2^3^4^5^6^7^8^9)^(2^3^4^5^6^7^8^9) greater than grahams number? I don't have a proof, but I know what Grahams number is and your number is so much smaller that there is no word to compare them... Grahams number is so huge, it's crazy.- SumThePrimes
- Post #2
- Forum: Linear and Abstract Algebra
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Graduate How Can the Infinite Product of (1+n^-2) Be Bounded?
Wow, thank you, I am acquainted with the sines of imaginary numbers and that formula, but it never even crossed my mind... So much for e^(4*pi^2)-1 ... I wouldn't have thought an exact solution... Maybe Euler is better at infinite products than me(Just maybe...:rolleyes: ), I actually got this...- SumThePrimes
- Post #3
- Forum: Calculus
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Graduate How Can the Infinite Product of (1+n^-2) Be Bounded?
I was wondering about the product n=1 to infinity of (1+n^-2) , I used a very unorthodox, to say the least, manipulation of complex numbers that shows that it should equal a particular number larger than 10^17 , however wolfram alpha can't seem to give me a answer, and when I sum to very large...- SumThePrimes
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- Infinite Product
- Replies: 2
- Forum: Calculus
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Graduate Antiderrivative of e^(-x)*sin(x)*x^n
Ah, thank you very much, I should have consulted wolfram alpha. I'm sure I'll have enough for a proof of it now, thank you! My summing of divergent resulted in the common answer 1+2+3+4...=-1/12, though I can now compute 2*1-4*3+6*5-8*7..., or indeed any n!/1-(n+3)!/3!+(n+5)!/5!-(x+7)!/7...- SumThePrimes
- Post #6
- Forum: Calculus
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Graduate Antiderrivative of e^(-x)*sin(x)*x^n
Well I have tried integration by parts on it, but it seemed to just explode to astronomical sizes... I have calculated it for certain values of n, and am rather sure that it can be expressed with common functions for any integer, and in particular I only need the Integral from 0 to infinity of...- SumThePrimes
- Post #3
- Forum: Calculus
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Graduate Antiderrivative of e^(-x)*sin(x)*x^n
I have recently come up with a fascinating method of summing various divergent series, whether it has been done before I am unaware, but in some scenarios it involves the anti-derivative of e^(-x)*sin(x)*x^n with respect to x. I only need positive integer values of n, and of course a...- SumThePrimes
- Thread
- Replies: 5
- Forum: Calculus