Decades: 1230s BC 1220s BC 1210s BC 1200s BC 1190s BC - 1180s BC - 1170s BC 1160s BC 1150s BC 1140s BC 1130s BC
Significant People
... 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 we add the square of b/(2a) to both sides, ...