Not sure I follow this as it looks suspiciously straightforward for a '3'.
((x+y)^(1/3))^3 is just a long-winded way of saying (x+y), equivalent in this case to n(n+1)/2, while (x^(1/3)+y)^3 is equivalent to (n(n+1)/2)^3. so it is either the triangular numbers or the cube of the triangular numbers.
Am I missing something?
Is there a problem with the problem?
Posted by broll
on 2011-02-03 13:48:13