Answer:
a = -1/2
Step-by-step explanation:
In order for the triangle with a base of 4-1 = 3 units to have an area of 3 square units, the height of it must be 2. Since the parabola opens downward, the y-intercept of the equation must be -2. Filling in known values for that point, we have ...
-2 = a(0 -1)(0 -4)
-2 = 4a . . . . . . . . . simplify
-2/4 = a = -1/2
