Which function has a range of {y|y ≤ 5}?
f(x) = (x – 4)2 + 5
f(x) = –(x – 4)2 + 5
f(x) = (x – 5)2 + 4
f(x) = –(x – 5)2 + 4

Since the range has less than sign, this means that the parabola is facing downwards and it means that a is negative.
Range is given by {y|y ≤ k}, and the vertex for of a quadratic equation is given by
Since the range is {y|y ≤ 5}, this means that k = 5 and since a is negative
The correct function is