Question

NEED ANSWER ASPA.... PLS HURRY

Answer 1

We have that
$y=- x^{2} +36$

we know that
Is the equation of a vertical parabola open down
so
the vertex is a maximum

step 1
convert the equation of the parabola in the vertex form
$y=- x^{2} +36 \\ y-36=- x^{2}$

the vertex (h,k) is the point (0,36)

Part a) The point on the graph where the height of the tunnel is a maximum is (0,36)

Part b) The points on the graph where the height of the tunnel is zero feet is when y=0
so
for y=0
$- x^{2} +36=0 \\ x^{2} =36 \\ x= (+/-) 6$

the points are (-6,0)  and (6,0)

see the attached figure