Find the slope 7-12 please

How do you solve a question like this?

Heather is riding a quadratic function that represents a parabola that touches but does not cross the x-axis at x=-6

Suppose that the function f is defined. , for all real numbers, as follows. _ \ 1/4x² -4 if x≠ -2 f(x)=< /_-1 if x=-2 find f(-5), f(-2), and f(4)