Who can give me a hint of how to calculate this integral,Thanks

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Discussion Overview

The discussion revolves around the calculation of a specific integral involving arcsine and polynomial terms. Participants explore methods for evaluating the integral, including numerical solutions and software tools for visualization.

Discussion Character

  • Homework-related, Mathematical reasoning, Technical explanation

Main Points Raised

  • A participant presents the integral to be evaluated, which involves the function \(y^2 \arcsin\left(\frac{a+y}{\sqrt{196-y^2}}\right)\).
  • Another participant notes the lack of an explicit evaluation but finds the numerical solutions interesting.
  • There are inquiries about the software used for expressing the curve related to the integral and whether a formula exists for it.
  • One participant mentions using GNU Octave for numerical evaluation and provides a code snippet for calculating the integral.
  • Another participant shares their experience using PTC Mathcad Prime 3.0, indicating that it allows for straightforward input of the expression.

Areas of Agreement / Disagreement

Participants do not reach a consensus on the evaluation of the integral, as multiple approaches and tools are discussed without a definitive solution being presented.

Contextual Notes

The discussion does not clarify the assumptions or conditions under which the integral is evaluated, nor does it address potential limitations of the numerical methods mentioned.

Who May Find This Useful

This discussion may be useful for individuals interested in numerical integration techniques, software tools for mathematical computations, or those seeking assistance with similar integral problems.

zhaojx84
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View attachment 7756
$$\int_{0}^{\frac{-a}{2}+\frac{\sqrt{392-{a}^{2}}}{2}} {y}^{2}\arcsin\left({\frac{a+y}{\sqrt{196-{y}^{2}}}}\right)\,dy$$
 

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I'm not seeing an explicit evaluation, but I found the numerical solutions fascinating:View attachment 7762
 

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tkhunny said:
I'm not seeing an explicit evaluation, but I found the numerical solutions fascinating:

Thanks very much. Could you tell me which software did you use to express this curve? Is there a formula for this curve. Thanks again for your help.
 
zhaojx84 said:
Thanks very much. Could you tell me which software did you use to express this curve? Is there a formula for this curve. Thanks again for your help.

Hi zhaojx84, welcome to MHB! (Wave)

In GNU Octave, the free version of MatLab, we can do:
Code:
f = @(a, y) y^2 * asin((a + y) / (sqrt(196 - y^2)));
g = @(a) quad(@(y) f(a, y), 0, (-a / 2 + (sqrt(392 - a^2)) / 2));
x = -11:0.2:14;
y = arrayfun(g, x);
plot(x, y);

In Octave Online, we can quickly see what it does.

View attachment 7768
 

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zhaojx84 said:
Thanks very much. Could you tell me which software did you use to express this curve? Is there a formula for this curve. Thanks again for your help.
I used PTC Mathcad Prime 3.0

It required pretty much what you see. Just type in what you want. The algebraic interpretation is provided.
 

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