21
Shubhodip
·2011-11-16 11:14:05
P(x)^2 = P(-x)^2
P(x) = P(-x)
or P(x)+ P(-x) = 0
If P(x) + P(-x) = 0
P(0) = 0
P(1) = 1
P(2) = P(1)^2 + 1= 2
P(5) = P(2)^2 + 1= 5
There may exists lot of solutions,can u give us the source?
21
Arnab Kundu
·2011-11-16 20:18:07
The source is Ramanujan School of Mathematics RMO Practice test
21
Arnab Kundu
·2011-11-16 20:21:30
I got only 2 solutions during the test P(x)=x and P(x)=|x|
Here goes Prophet sir's solution:http://www.goiit.com/posts/list/algebra-sir-please-reply-me-72058.htm#354976
and PCO's solution: http://www.artofproblemsolving.com/Forum/viewtopic.php?f=57&t=446051&p=2510734#p2510734
262
Aditya Bhutra
·2011-11-16 23:33:31
p(x)=[x] will also be one of the solns.