The opening of the tunnel can be modeled by the graph of the equation y=-0.18x^2+4.4x-12 where x and y are measured in feet. Find the maximum height of the tunnel.

1. To find the vertex of a parabolla whose equation is written in the standard form, you must apply the following proccedure:

2. You have:

y=-0.18x²+4.4x-12

a=-0.18

b=4.4

3. You must apply the following formula:

x=-b/2a

x=-4.4/2 (-0.18)

x=-4.4/-0.36

x=12.22

4. When you susbtitute x=12.22 into the equation y=-0.18x²+4.4x-12, you obtain:

y=-0.18x²+4.4x-12

y=-0.18 (12.22) ² + 4.4 (12.22) - 12

y=14.88 feet

5. The answer is: The maximum height of the tunnel is 14.88 feet