M = {y l y = x² - 4x + 3,x∈R} = {y l y = (x - 2)² - 1,x∈R} = [-1 ,+∞)
N = {y l y = -x² + 2x + 8,x∈R} = {y l y = - (x - 1)² + 9 ,x∈R} = (-∞ ,9]
M ∩ N = [-1 ,9]