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Showing posts with the label Gamma function

@integralsbot \int_0^\infty \left(\sqrt{1+x^4}-x^2\right) \,dx=\frac{\Gamma^2\left( \frac14\right)}{6 \sqrt{\pi}}

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   Today we will show the following result that appears in this post from @integralsbot Let Then: And         We then get: By the reflection formula Letting we obtain that By the functional equation of the Gamma function We obtain for instance that

VARIATION OF BINET´S INTEGRAL

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In this post we obtain the following integrals We have previously proved the following result (1) Letting we obtain (2) From (2), we can easily obtain the following relations (3) Lemma 1 (4) Proof: From (4) and (3) we obtain In the same fashion we obtain Lemma 2: (5) From Lemma 2 and (3) we obtain: Similarly

MAMLSTEN INTEGRALS - PART I

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We will today prove the following integral that belongs to a family of log-log integrals known as Malmsten integrals  which Vardi´s integral is a particular case: Mamlsten Integrals (1) If we let      in (1) we obtain the desired result: (2) Appendix: Cauchy Product Example We have that and , we therefore obtain Evaluation of the integral: Recall the sine of a difference formula And The Fourier series for the LogGamma function proved here If we let       We obtain Or

Two Amazing Integrals

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Today we will prove the following two amazing integrals (1) (2) In order to prove (1), first recall the following results: (3) (4) Then, (5) If we let and in (5), we get (6) Where We used the result We can rewrite (6) as (7) If we now integrate (7) w.r. to z we have: The evaluation of the constant is a beautiful exercise per se. Fortunately relying on the previous estabilished Vardi´s integral We may accomplish it easily. Setting in the last equation, the L.H.S. becomes Where we used the Vardi´s integral proved here : And The R.H.S. becomes Equating L.H.S. and R.H.S. we conclude that And finally (8) Or (9) Appendix Recall Legendre Duplication Formula for the Gamma Function Letting