noun Mathematics. a method, usually of solving quadratic equations, by
which a quadratic
expression, as
x ^{2} − 4
x + 3, is written as the sum or difference of a perfect square and a constant,
x ^{2} − 4
x + 4 + 3 − 4 = (
x − 2)
^{2} − 1, by addition and subtraction of appropriate constant terms.