420 BC - Hippocrates begins the scientific study of medicine by maintaining that diseases have natural causes and puts forth the Hippocratic Oath, marking the birth of modern medicine
... square trinomial of the form x2 + 2xy + y2. Since "2xy" in this case is (b/a)x, we must have y = b/(2a), so we add the square of b/(2a) to both sides, ...