1) A firefighter aims a hose at a window 25 ft. above the ground. The equation

h = -0.01d^2 + 1.06d + 5
models the path of the water, when h equals height in feet. Estimate, to the nearest foot, the horizontal distance d in feet btween the firefighter and the building.

This problem confuses me a lot.

1 answer

25 = -0.01d^2 + 1.06d + 5
so
.01 d^2 - 1.06 d + 20 = 0
d^2 - 106 d + 2000 = 0

d = (1/2)[ 106 +/- sqrt (106^2 - 8000)]
d = .5 [ 106 +/- sqrt (3236)]
d = .5 [ 106 +/- 57 ]
d = 81.5
or
d = 24.5
If he shoots the water up into the window, he is 25 feet away but if he shoots the water up so that it enters the window on the way back down he can be 82 feet away.