algebra word problem, im rlly confused :(

[hannahr123]

how would I solve question c? I have no idea where to start and what to do. Thank you so much in advance!

 

[Steven G]

This is not a homework service forum. That is we do not do problems for students. We prefer to give them hints.
Draw the function. What is the top height? How long does it take to reach this top height?

Post back showing some work.

 

[Deleted member 4993]

how would I solve question c? I have no idea where to start and what to do. Thank you so much in advance!

So then:

start with "finding out" what does the problem want you to solve.

The question states "Of the time the ball stays in the air, how much of it is the ball going up..."

What should happen to f(t)

when the ball is going up?

that is - during this time of "ball going upward", the value of f(t) is increasing with (t) or decreasing with (t).

If you follow the instruction in response #2, and plot f(t) vs. t, you will be able to visualize the problem.

Do it and let us know.

 

[HallsofIvy]

Notice that \(\displaystyle -16t^2+ 80t= -16(t^2+ 5t)\). Complete the square inside the parentheses. That is a parabola. What does the fact that -16 is negative tell you about the parabola?