Question

[9.06] Rebekah kicks a soccer ball off the ground and in the air with an initial velocity of 25 feet per second. Using the formula H(t) = −16t2 + vt + s, what is the maximum height the soccer ball reaches?

9.5 feet

9.8 feet

10.2 feet

10.7 feet

Answer 1

Need help!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

Answer 2

You are basically trying to find the x value of the turning point of the parabola.

Answer 3

I meant y sorry!

Answer 4

will it be B then i don't know

Answer 5

H(t)= -16t^2+25t+0

So the maximum height is at the vertex. t = -b/2a= -25/ (2*-16)= 25/32 sec or about .78sec
Plug into H(t)
H(25/32)= -16(.78)^2+25(.78)= 9.77 ft or about 9.8 ft

Answer 6

am i right

Answer 7

Yeah you got it :)

Answer 8

cool thanks

Answer 9

can you help on this...

[9.01] Determine whether the graph of y = x2 − 4x + 1 has a maximum or minimum point, then find the maximum or minimum value.

Minimum; (2, -3)

Maximum; (2, -3)

Minimum; (-3, 2)

Maximum; (-3, 2)

Answer 10

The x^2 is positive so...?

Answer 11

its up

Answer 12

Yeah and that means?

Answer 13

its Minimum

Answer 14

That's it

Answer 15

What would you do next?

Answer 16

Now its either a or c.

Answer 17

i thought it be A

Answer 18

That's correct.

Answer 19

You already did the -b/2a and substituted the result in the equation.