by RonPurewal Wed Nov 23, 2011 7:07 am
... or you can just plug numbers. in just about any INEQUALITY situation, PLUGGING EXTREMES is a good way to determine behavior.
here, it's quite obvious that the answer to the question can be "yes", i.e., that the sum can be greater than 1. therefore, the essence of the problem lies in trying to make the sum less than 1.
fortunately, since such specific boundaries are given, this is a straightforward task: just consider the lower extremes of those ranges, i.e., numbers just above 1/2.
if p = a little bit more than 1/2 (like 0.500001) and q = same, then p^2 + q^2 will be a little more than 1/4 + 1/4, or a little more than 1/2.
that's less than 1, so, insufficient.