Answer:
f(x) = -x² + 2x + 4
Step-by-step explanation:
We have quadratic functions f(x) = ax² + bx + c.
c - y-intercept
If a > 0, then a parabola opens up and has a minimum in a vertex.
If a < 0, then a parabola opens down and has a maximum in a vertex.
The function has maximum and y-intercept of 4:
a < 0 and c = 4
