Question

Tim kicks a ball off the ground. After t seconds, its height, h (in feet), is given by the formula h=-16t^2+64t. What is the maximum height reached by the ball?
80 feet
64 feet
48 feet
16 feet

Answer 1

try plugging in each of your options into the formula as h

Answer 2

Try to calculate h'(t)=0 and plug that result into h(t)

Answer 3

wait, im confused...

Answer 4

with what?

Answer 5

what you just said

Answer 6

okay i explain

Answer 7

h(x) is a parabola right?

Answer 8

i guess

Answer 9

tha maximum height of a ball or a parabola is at the point where the slope of it is 0.
The slope dy/dt =0
t

Answer 10

so iput in h(0) then the rest of the formula?

Answer 11

no
you have to calculate h'(t) =0

Answer 12

\[-32t+64=0 \]
\[-t=-2\]
\[t=2\]

Answer 13

Now you have t and can plug it in to h(t) => h(2).

Answer 14

so i pput h(2) then the rest or the formula?

Answer 15

h(2) = -16(2)^2 +64(2)

Answer 16

i got 32, which isnt an answer choice

Answer 17

-16(2)^2 is -64 | 64(2) is 128

Answer 18

128-64 is 64

Answer 19

thank you (: your awsome!

Answer 20

No problem!