MHB How to calculate this type of integral, Thanks

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The discussion centers on the difficulty of calculating two specific integrals involving arcsine functions. The first integral is deemed unsolvable using Wolfram Dev Platform, while the second integral is acknowledged as messy but manageable. The provided Wolfram Language code yields a complex expression that includes logarithmic and inverse tangent functions, suggesting that the result is not very practical for use. Despite the complexity, it is considered the best available solution for the indefinite integral. Overall, the conversation highlights the challenges of integrating these specific mathematical functions.
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$$\int {z}^{2}\arcsin\left({\frac{a+\sqrt{392-{a}^{2}-2{z}^{2}}}{2 \sqrt{196-{z}^{2}}}}\right) dz$$
$$\int {z}^{2}\arcsin\left({\frac{a}{\sqrt{196-{z}^{2}}}}\right) dz$$
 

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Hmm. For the first integral, I would sit down and cry. Wolfram Dev Platform doesn't do anything with it. The second integral is doable, but extremely messy. The Wolfram Langauge code
Code:
FullSimplify[Integrate[z^2 ArcSin[a/(Sqrt[196-z^2])],z] ]//TeXForm
yields
$$\frac{1}{6}\left(-a\sqrt{196-z^2}z\sqrt{\frac{a^2+z^2-196}{z^2-196}}+2744i
\left(\ln\left(\frac{3i\left(ia\sqrt{196-z^2}
\sqrt{\frac{a^2+z^2-196}{z^2-196}}+a^2-14(z+14)\right)}{686a^2
(z+14)}\right)-\ln\left(\frac{3\left(a\sqrt{196-z^2}
\sqrt{\frac{a^2+z^2-196}{z^2-196}}-ia^2-14i(z-14)\right)}{686a^2
(z-14)}\right)\right)-a\left(a^2-588\right)\tan
^{-1}\left(\frac{z}{\sqrt{196-z^2}\sqrt{\frac{a^2+z^2-196}{z^2-196}}}\right)+2
z^3\sin^{-1}\left(\frac{a}{\sqrt{196-z^2}}\right)\right).$$
I did tinker with this output just a hair (log to ln). This is not a very useable solution, but I think it's the best you're going to get for an indefinite integral.
 
Ackbach said:
Hmm. For the first integral, I would sit down and cry. Wolfram Dev Platform doesn't do anything with it. The second integral is doable, but extremely messy. The Wolfram Langauge code
Code:
FullSimplify[Integrate[z^2 ArcSin[a/(Sqrt[196-z^2])],z] ]//TeXForm
yields
$$\frac{1}{6}\left(-a\sqrt{196-z^2}z\sqrt{\frac{a^2+z^2-196}{z^2-196}}+2744i
\left(\ln\left(\frac{3i\left(ia\sqrt{196-z^2}
\sqrt{\frac{a^2+z^2-196}{z^2-196}}+a^2-14(z+14)\right)}{686a^2
(z+14)}\right)-\ln\left(\frac{3\left(a\sqrt{196-z^2}
\sqrt{\frac{a^2+z^2-196}{z^2-196}}-ia^2-14i(z-14)\right)}{686a^2
(z-14)}\right)\right)-a\left(a^2-588\right)\tan
^{-1}\left(\frac{z}{\sqrt{196-z^2}\sqrt{\frac{a^2+z^2-196}{z^2-196}}}\right)+2
z^3\sin^{-1}\left(\frac{a}{\sqrt{196-z^2}}\right)\right).$$
I did tinker with this output just a hair (log to ln). This is not a very useable solution, but I think it's the best you're going to get for an indefinite integral.

Thank you very much. Regards.
 
There are probably loads of proofs of this online, but I do not want to cheat. Here is my attempt: Convexity says that $$f(\lambda a + (1-\lambda)b) \leq \lambda f(a) + (1-\lambda) f(b)$$ $$f(b + \lambda(a-b)) \leq f(b) + \lambda (f(a) - f(b))$$ We know from the intermediate value theorem that there exists a ##c \in (b,a)## such that $$\frac{f(a) - f(b)}{a-b} = f'(c).$$ Hence $$f(b + \lambda(a-b)) \leq f(b) + \lambda (a - b) f'(c))$$ $$\frac{f(b + \lambda(a-b)) - f(b)}{\lambda(a-b)}...

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