Use the quadratic formula to solve the problem.
A soccer player throws the ball onto the field from the sideline. An equation modeling the ball's flight is h = -16t2 + 18t + 2. In how many seconds will the ball reach the ground?
A. in about 2 seconds
B. in about 1.2 seconds
C. in about 1.8 seconds
D. Cannot be determined

Question

Use the quadratic formula to solve the problem.
A soccer player throws the ball onto the field from the sideline. An equation modeling the ball's flight is h = -16t2 + 18t + 2. In how many seconds will the ball reach the ground?
A. in about 2 seconds
B. in about 1.2 seconds
C. in about 1.8 seconds
D. Cannot be determined

directrix · Answer

The ball hits the ground when h = 0.  The question is to find when -16t2 + 18t + 2= 0.
-16t2 + 18t + 2= 0
Divide through by -2
8t^2 - 9t - 1 = 0
This quadratic appears not to factor.
So, use the quadratic formula to find the roots, one of which will be the answer to the question.

anonymous · Answer

^_v huh

directrix · Answer

Read about the quadratic formula at the link. http://www.purplemath.com/modules/quadform.htm

anonymous · Answer

I already did but I don't understand it

directrix · Answer

Well, copy the quadratic formula and post it here. Then, we'll figure out the a, b, and c values. If you do not want to use the quadratic formula, then suggest some other technique and I'll try to help you with that.

anonymous · Answer

ok