Recent content by Belgium 12

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    Graduate Psi function or digamma function?

    Hi everyone, concerning serie representation of psi function. In te solution of bessel function of the second kind we have the following expressions for the psi functions psi(m+1) and psi(n+m+1) then they give the series for the two psi functions ie(or digamma function) sum k from 1 to m of...
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    Graduate Question about computing residues after substitution

    Hi, thank you very much for the answer Belgium 12
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    Graduate Question about computing residues after substitution

    Hi members, See attacged PDF file for my question Thank you
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    Undergrad How Does Log(z) Expand at Infinity?

    Hi, see attached PdF file for my question concerning serie expansion of log(z) at infinity. Thank you Belgium 12
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    Undergrad What is the difference between d/dx and d/d(x^2) in differentiation notation?

    Hi members, see attached PdF file. What's the difference between d/dx and d/d(x^2) I don't understand this notation?? Thank You
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    Undergrad Laplace transform using differential equations

    Hello Mark 44, If I understand it,Y'(0)=infinity.Here infinity can be treated as a constant. Thank you
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    Undergrad Laplace transform using differential equations

    Hi members, Laplace transform using differential equations.(see attached PDF file) My question d/ds(s^2 y- s Y(0)-Y'(0).)... Y(t)=sin(sqrt(t)) Y(o)=0 Now Y'= cos(sqrt(t)/2sqrt(t) Y'(0)=infinity d/ds (Y'(0)=?? can it be treated as a constant or can we change limit and differentiation??I...
    • Belgium 12
    • Thread
    • Differential Differential equations Laplace Laplace transform Transform
    • Replies: 2
    • Forum: Calculus
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    Undergrad How Does the Denominator x+a Become 1-t in Integral Substitution?

    Hi members, see attached Pdf file. For a<0,write b=-a and let x=bt.Then My question: how becomes the denominator x+a to 1-t? I don't see it Thank you
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    Undergrad Factorial Notation for Gamma Function Expression with Fractional Input?

    Hi members, gamma (n+1)=n! Now I have the following: gamma(2(n+3/2))=gamma(2n+1) What is factorial notation for this?? Thank you
    • Belgium 12
    • Thread
    • Factorial Function Gamma Gamma function
    • Replies: 9
    • Forum: Calculus
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    Graduate How to Integrate 1/sinh^2(x/2)?

    Hi dear members, Sorry for my mistake with coth(x/2). to pwsnafu:I want to integrate integral from -inf to +inf of 1/sinh^2(x/2) Thank you
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    Graduate Is the Integral of 1/sinh^2(x/2) a Principal Value Integral?

    Hi dear members, I have a problem with the following integral: Integral 1/sinh^2(x/2) from -inf to +inf =-2 coth(x/2) must I consider it as a principal value integral? Thank you
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    Graduate Summation with exponential functions

    Dear members, see attached pdf file.Can you help me to prove this formulas. Thank you Belgium 12 This is not homework.I'm 68 and retired.
    • Belgium 12
    • Thread
    • Exponential Functions Summation
    • Replies: 2
    • Forum: Calculus
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    Undergrad Fourier Transforms: Get Help with Your Questions

    Hi members, I have a problem with Fourier transforms. There are two attached Pdf files. My questions are on the Pdf files.Give me a little help. Thank you Belgium 12
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    Undergrad Problem with two trigonometric integrals

    Hi I have a little problem with the integrals of the following functions. integral from 0to 2pi ∫sin^2(nθ+ψ)dθ=∫cos^2(nθ+ψ)dθ=pi ψ=the phase angle.They occur in the theory of vibrations. Is it appropriate to set ψ=0 Thank you
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    Fortran Hi,Below is a fortran program to calculate the roots of an

    Fortran Hi, Thanks to Uart for his help.I changed the program with your suggestions and it works fine. Here is the program:! ! Numerical Mathematics and Computing, Fifth Edition ! Ward Cheney & David Kincaid ! Brooks/Cole Publ. Co. ! Copyright (c) 2003. All rights reserved. ! For...