In: Advanced Math
Show that every Pythagorean triple (x, y, z) with x, y, z having no common factor d > 1 is of the form (r^2 - s^2, 2rs, r^2 + s^2) for positive integers r > s having no common factor > 1; that is
x = r^2 - s^2, y = 2rs, z = r^2 + s^2.