Proof of Ramanujan's Problem 525 with A=5, B=4

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Discussion Overview

The discussion revolves around the proof of Ramanujan's problem 525, specifically for the values A=5 and B=4. Participants explore the validity of a proposed equation and its implications, examining whether it holds true across various cases.

Discussion Character

  • Exploratory, Debate/contested, Mathematical reasoning

Main Points Raised

  • One participant presents a proof attempt involving the equation $$\sqrt{A^{1/3}-B^{1/3}}=\frac{(A*B/10)^{1/3}+(A \times B)^{1/3}-(A^2)^{1/3}}{3}$$ for A=5 and B=4, questioning its correctness.
  • Another participant challenges the proof by stating that the two sides of the equation are not generally equal, suggesting testing with A=8 and B=0 as a counterexample.
  • A third participant questions the validity of the proposed equation by providing specific cases (A=1, B=1 and A=27, B=28) where it does not hold, arguing that a valid equation must be true for all values of A and B.
  • The original poster acknowledges the feedback and expresses intent to find the correct equation.

Areas of Agreement / Disagreement

Participants do not agree on the correctness of the proposed proof, with multiple competing views regarding the validity of the equation presented. The discussion remains unresolved.

Contextual Notes

Participants highlight that the proposed equation may not hold for all values of A and B, indicating potential limitations in the proof's applicability.

Ted7
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Hi everyone.
This is my proof (?)of ramanujan's problem 525: http://www.imsc.res.in/~rao/ramanujan/collectedpapers/question/q525.htm (link to problem)

[![enter image description here][1]][1]

$$
\sqrt{A^{1/3}-B^{1/3}}=\frac{(A*B/10)^{1/3}+(A \times B)^{1/3}-(A^2)^{1/3}}{3} \Leftrightarrow \\
9 \times (A^{1/3}-B^{1/3})=[(A*B/10)^{1/3}+(A \times B)^{1/3}-(A^2)^{1/3}]^2
$$
for A=5 and B=4. we arrive to the final result

$$
R=R \qquad (R=9 \times (A^{1/3}-B^{1/3}))
$$

Is this proof correct?
If it isn't am I getting closer to the right answer?

[1]: https://i.stack.imgur.com/AP8hC.jpg
If you've seen this posted elsewhere ,notice that I posted it.
Thank you for your help!.
 
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You left out all steps apart from one. If you can show that the two sides are equal, that works, but in general they are not equal. As an example, try A=8, B=0.
 
How did you come to the conclusion of:
$$\sqrt{A^{1/3}-B^{1/3}}=\frac{(A*B/10)^{1/3}+(A \times B)^{1/3}-(A^2)^{1/3}}{3} $$
the ecuation don't work for
the case A=1 , B=1
and the case of A= 27, and B=28
so is incorrect.

is like tell
$$A=A^{2}$$
for A=1 and A=0, we arrive to the final result
$$A=A^{2}$$
but this is obviously wrong, you can not "create" ecuations for Particular cases, If an equation is right
Must be true for all values of A
 
Thanks I was aware of it .I am going try to find the right equation ;)
 

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