MathDB
c = a + b/a -1/b is perfect square.

Source: New Zealand NZMOC Camp Selection Problems 2013 p8

September 19, 2021
Perfect Squarenumber theory

Problem Statement

Suppose that aa and b b are positive integers such that c=a+ba1bc = a +\frac{b}{a} -\frac{1}{b} is an integer. Prove that cc is a perfect square.