All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Numbers
Prime Pairs satisfy Quintic = Cubic (Posted on 2024-02-17) Difficulty: 3 of 5
Given that each of p and q is a prime number:

Determine all possible pairs (p,q) that satisfy this equation:

        p(p4+p2+10q) = q(q2+3)

See The Solution Submitted by K Sengupta    
Rating: 5.0000 (1 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
re(2): Analytic solution with computer verification | Comment 5 of 7 |
(In reply to re: Analytic solution with computer verification by Brian Smith)

You're right; I made a blunder.
My prior note was not a proof at all.

The truth is: RHS, q(q^2+3) is always positive
(p^4+p^2+10q) is always positive
So p can be even or odd.

I did the computer run first, and I think seeing that apparently p=2 was the only solution I was led down the primrose path and jumped to a conclusion (that parity would be the key to a proof).  I barely looked at the LHS expression at all.

Will make a note in the earlier post.

  Posted by Larry on 2024-02-18 09:23:00
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (1)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (14)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2024 by Animus Pactum Consulting. All rights reserved. Privacy Information