Answer:
4
Step-by-step explanation:
Area of Triangular region (A) = a x b
b = 4 - a (for point (a,b) and x + y = 4)
A = a x (4 - a) = - a² + 4a = -(a² - 4a + 4) + 4 = - (a - 2)² + 4
in the formula of parabola y = a(x - h)² + k, a= -1 the graph is pointed down where h=2 and k=4
The vertex is (2, 4)
The maximum area of triangular region is 4
