Find a formula for this sequence

  • Thread starter Thread starter nate9228
  • Start date Start date
  • Tags Tags
    Formula Sequence
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
1 reply · 2K views
nate9228
Messages
42
Reaction score
0

Homework Statement


A sequence (xj) where j can go from 0 to infinity satisfies the following:
(1) x1= 1 and
(2) for all m≥n≥0, xm+n+ xm-n= (1/2)(x2m+x2n)
Find a formula for xj and prove that the formula is correct


Homework Equations





The Attempt at a Solution


All I have done so far is is play around with m and n values so far and I think a proper formula:
xj= j2. Now I would have to prove this (for which I plan to use induction most likely) but I wanted to see if I was on the write track in my thinking.
 
Physics news on Phys.org
nate9228 said:

Homework Statement


A sequence (xj) where j can go from 0 to infinity satisfies the following:
(1) x1= 1 and
(2) for all m≥n≥0, xm+n+ xm-n= (1/2)(x2m+x2n)
Find a formula for xj and prove that the formula is correct


Homework Equations





The Attempt at a Solution


All I have done so far is is play around with m and n values so far and I think a proper formula:
xj= j2. Now I would have to prove this (for which I plan to use induction most likely) but I wanted to see if I was on the write track in my thinking.

Looks fine to me. Now try and check it. Induction isn't really necessary. Just check that your guess works.