Question

No one will help me with this question...
Can someone please help?
I'll give a metal.

Answer 1

A toy rocket was launched from the ground. The function f(x) = -16x2 + 256x shows the height of the rocket f(x), in feet, from the ground at time x seconds.
What is the axis of symmetry of the graph of f(x), and what does it represent? (3 points)


x = 8; it takes 8 seconds to reach the maximum height and 8 seconds to fall back to the ground

x = 16; it takes 16 seconds to reach the maximum height and 16 seconds to fall back to the ground

x = 8; it takes 8 seconds to reach the maximum height and 16 seconds to fall back to the ground

x = 16, it takes 16 seconds to reach the maximum height and 32 seconds to fall back to the ground

Answer 2

Still need help on this?

Answer 3

yeah ):

Answer 4

Ok, the axis of symmetry is measured by

-b/2a

You know what your b and a values are?

Answer 5

no...

Answer 6

I'll warn you now. I'm horrible with math.

Answer 7

A quadratic's standard form is

ax^2+bx+c

-16x^2 + 256x

There is no c value here, but a and b values are clearly here. Can you tell me what they are?

Answer 8

wait. wouldnt a- 16 and then b- 256

Answer 9

Exactly, so plug into -b/2a

-256/-32=?

Answer 10

256/ -64 =-4

Answer 11

oh wait. its just 4 because 256 isnt positive

Answer 12

@dtan5457

Answer 13

B=256
A=-16

-b=-256
2a=-32

-256/-32=?

Answer 14

8?

Answer 15

Yep, so immediately you can cross out B and D from your answer choices

Answer 16

Now, since 8 is the axis of symmetry, it takes 8 seconds for the rocket to reach full height. To know what the time it takes for it to fall back to the ground...y must equal 0.

The choices are either 8 or 16.

Plug 8 and 16 to

-16^x2 + 256x, and see which one equals 0.

Answer 17

I'd plug the two into x right

Answer 18

Yep, one by one.

Answer 19

so itd be c?

Answer 20

@dtan5457

Answer 21

Yep! 16 would make the y=0.

Answer 22

thank you!

Answer 23

yw