+0

0
67
1

The equation y = x^2 - 18x - 33 describes the height (in feet) of a ball tossed up in the air at 26 feet per second from a height of 105 feet above the ground. In how many seconds will the ball hit the ground? Express your answer as a decimal rounded to the nearest tenth.

Jan 24, 2021

#1
0

When the ball hits the ground , height, y, = 0

0 = x^2 -18x-33     Use Quardratic formula   a = 1   b = -18    c= -33

$$x = {-b \pm \sqrt{b^2-4ac} \over 2a}$$     to find   x = 9 +- sqrt 114        throw out the negative value

x = 9 + sqrt 114 =~ 19.7 s

Jan 24, 2021