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

Home > Just Math
Quadratic Quandary (Posted on 2013-11-04) Difficulty: 3 of 5
g(x) is a quadratic function given by:
g(x) = x2 + 12x + 30.

Determine all possible real roots of this equation:
g(g(g(g(g(x))))) = 0

No Solution Yet Submitted by K Sengupta    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
Solution re: approximate - exact | Comment 2 of 6 |
(In reply to approximate by Jer)

on closer inspection the
(-12+√(12-4(30-[ans]))/2 [enter]
simplifies to
-6+√(6+[ans])

if you plug this into itself you get
-6+√(6+[-6+√(6+[ans])] = -6+√√(6+[ans]) = -6 + (6+ans)^(1/4)
if you do this five times and since the original [ans]=0
you get the exact solution
-6+6^(1/32)

  Posted by Jer on 2013-11-04 15:49:37

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 - 2017 by Animus Pactum Consulting. All rights reserved. Privacy Information