Solve x2−y2=0x^2 - y^2 = 0x2−y2=0 for integers.
x=±yx = \pm yx=±y
x=0,y=0x = 0, y = 0x=0,y=0 only
x=yx = yx=y only
x=1,y=1x = 1, y = 1x=1,y=1