Question

The function f(x) = –x2 – 4x + 5 is shown on the graph.

On a coordinate plane, a parabola opens down. It goes through (negative 5, 0), has a vertex at (negative 2, 9), and goes through (1, 0).
Which statement about the function is true?

The domain of the function is all real numbers less than or equal to −2.
The domain of the function is all real numbers less than or equal to 9.
The range of the function is all real numbers less than or equal to −2.
The range of the function is all real numbers less than or equal to 9.

Answer 1

the last one : the range of the function is all real numbers less than our equal to 9.

Explanation:

it is a parabola that opens up only down. that means all the calculated y-values go deeper and deeper into lower and negative values the more right or left we go on the x-axis.

the maximum y-value we have at the vertex with y=9. no other x-value can generate a bigger y-value.

that's why the last answer option is right.