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

Home > Just Math
Squares joining quadratics (Posted on 2010-02-24) Difficulty: 3 of 5
A and B are points on the graph y=x2+8x+7
C and D are points on the graph y=-x2+8x-7
and ABCD is a square.

Find all possible x-coordinates of point A

See The Solution Submitted by Jer    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
re(2): computer exploration (there is a 4th. a hint) | Comment 3 of 5 |
(In reply to re: computer exploration (possible spoiler) -- two more squares by Charlie)

There are 4 solutions.  Charlie has found 3 via some hard crunching but there is a not-so-difficult analytic solution.

Hint:
The two parabolas are rotations of each about the origin.  This puts some limitations on the square. 
  Posted by Jer on 2010-02-26 15:01:36

Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (6)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2014 by Animus Pactum Consulting. All rights reserved. Privacy Information