Find all positive integers n which make the expression below an integer:

(25/2 + (625/4 - n)^½ )^½ + (25/2 - (625/4 - n)^½ )^½

(In reply to re(2): Simplifying matters (Spoiler) (some thoughts) by Steve Herman)

correct you are.  Your comment prompted me to double check my work and the problem is that I forgot to multiply by 2 in the end when simplifying.  And so I now agree with your solution and it does indeed appear that for n>625/4 the imaginary parts cancel out and we end up with an integer value for odd n.

Posted by Daniel on 2009-03-25 19:06:29