She married Prince Anatole Demidoff di San Donato on November 1, 1840 in Florence, Italy and hence became Princess Mathilde. They had no children.
... the expression to the left of "=", that will make it a perfect square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so ...