How Can These Two Integral Identities Be Proven?

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SUMMARY

The forum discussion centers on proving two integral identities involving the function \( F(\rho) \) and the variable \( x \). The first identity is established through integration by parts, yielding the equation \(\dfrac{d}{dx}\intop_{x}^{a}\dfrac{F(\rho)d\rho}{\sqrt{\rho^{2}-x^{2}}}=-\dfrac{F(a)x}{a\sqrt{a^{2}-x^{2}}}+x\intop_{x}^{a}\dfrac{d\rho}{\sqrt{\rho^{2}-x^{2}}}\dfrac{d}{d\rho}\left[\dfrac{F(\rho)}{\rho}\right]\). The second identity remains unresolved, prompting requests for assistance. Participants emphasize the importance of demonstrating prior effort in problem-solving before seeking help.

PREREQUISITES
  • Understanding of integral calculus, specifically integration by parts.
  • Familiarity with the properties of definite integrals.
  • Knowledge of differentiation under the integral sign.
  • Basic proficiency in mathematical notation and functions.
NEXT STEPS
  • Study the technique of integration by parts in detail.
  • Explore the concept of differentiation under the integral sign.
  • Review examples of proving integral identities in advanced calculus.
  • Practice solving similar problems to enhance problem-solving skills.
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Mathematics students, educators, and anyone interested in advanced calculus and integral identities will benefit from this discussion.

jarvisyang
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Prove two integral identities?

1. The following integral identity holds
\dfrac{d}{dx}\intop_{x}^{a}\dfrac{F(\rho)d\rho}{\sqrt{\rho^{2}-x^{2}}}=-\dfrac{F(a)x}{a\sqrt{a^{2}-x^{2}}}+x\intop_{x}^{a}\dfrac{d\rho}{\sqrt{\rho^{2}-x^{2}}}\dfrac{d}{d\rho}\left[\dfrac{F(\rho)}{\rho}\right]
Hints: this can easily proved by applying ingtegration by parts to the right hand side of the identity
2. But the following can also hold
\dfrac{d}{dx}\intop_{x}^{a}\dfrac{F(\rho)d\rho}{\sqrt{\rho^{2}-x^{2}}}=-\dfrac{F(a)a}{x\sqrt{a^{2}-x^{2}}}+\dfrac{1}{x}\intop_{x}^{a}\dfrac{\rho d\rho}{\sqrt{\rho^{2}-x^{2}}}\dfrac{d}{d\rho}F(\rho)
I can not figure out the second identity.Is there anybody can help me?I'm waiting for your excellent proof!
 
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We are not allowed to help in problems unless you demonstrate an effort to solve the problem yourself.
 
pwsnafu said:
We are not allowed to help in problems unless you demonstrate an effort to solve the problem yourself.
Actually, I have made a lot efforts. The first identity has been proved by myself. But as for the second identities, I have been thinking for a long time and I still can not figure it out.
 
jarvisyang said:
Actually, I have made a lot efforts. The first identity has been proved by myself. But as for the second identities, I have been thinking for a long time and I still can not figure it out.

Well, you know what you do in that case don't you? Show us what you tried even if it's stupid-looking. You know good cooks try again don't you? Yeah, they mess up but they don't get discouraged, then try the recipie again, and eventually they cookin' with kerosene and you wonder how they got so good. Try the recepie even if you burn the dish. The trying part is important.
 
jackmell said:
Well, you know what you do in that case don't you? Show us what you tried even if it's stupid-looking. You know good cooks try again don't you? Yeah, they mess up but they don't get discouraged, then try the recipie again, and eventually they cookin' with kerosene and you wonder how they got so good. Try the recepie even if you burn the dish. The trying part is important.

OK.Thank you for your suggestion, jackmell. I've got it. I will post my question together with my efforts or scripts next time.
 

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