Question

I need help understanding two questions..
Which function has vertex (2, 0) and contains the point (3, 4)?
(Points : 1)
y = x2 4x + 4

y = 2x2 8x + 8

y = 4x2 4x + 4

y = 4x2 16x + 16

Answer 1

I think you missing a bunch of signs on your answers..

Answer 2

I think its C

Answer 3

Please fix your answers or it's impossible to answer lol

Answer 4

Yeah. You probably want to either graph this. Or put everything into vertex form.

for example

y=x^2-4x+4
you don't need to complete the square for this one.

it is simply (x-2)^2

vertex=2,0

Answer 5

so it's not the first one

Answer 6

y=2x^2-8x+8

that's just the first one multiplied by 2, so it's not that either

Answer 7

Oh what am I doing..the vertex IS 2,0.

Answer 8

I used the formula y=a(x-h)^2-k and got a=4 so then I put it into the equation and I got y=4(x-2)^2-0 So I then got y=-8

Answer 9

SO it's actually definitely not C, because the vertex is no where near 2,0

Answer 10

C's vertex is 0,5,3

Answer 11

So how do I find the vertex?

Answer 12

It's the last one..because

y=4x^2-16x+16

y=4(x^2-4x+4)

y=4(x-2)^2

vertex=2,0

plug in 3 and you get

y=4(3-2)^2

y=4

so D is correct

Answer 13

Wait but how did you know it was 16??

Answer 14

y=4x^2-16x+16

that was the original answer

Answer 15

that's what it says on your link

Answer 16

Yea but do I just go through the answers until I find the right one?

Answer 17

Technically, you would put each one into vertex form. Then plug 3 as the x value and see if y comes out as 4

Answer 18

Okay, can you help with one more problem?

Answer 19

sure

Answer 20

What is the equation of a quadratic function with vertex (0, 0) and containing the points (1, 1), and (1, 1)?
(Points : 1)
y = x2

y = x2

y = x2 1

y = x2 + 1

Answer 21

broken answer choices again

Answer 22

containing the points (1, 1), and (1, 1)?

Answer 23

It's either x^2 or -x^2, as both vertex is 0,0.

Answer 24

Plug in the x coordinates and see if the correct y comes out,

Answer 25

Which one do you think it is?

Answer 26

Idont know I am comletley lost on this one

Answer 27

You need to get the points 1,-1 and -1, 1

-(x^2)

solve: -(1^2)
solve: -(-1^2)

Answer 28

*-1,-1

Answer 29

Do you get -1 for both answers?

Answer 30

No just -1,1^2

Answer 31

-(-1^2) is not -1?

Answer 32

Yes it is

Answer 33

then your answer is -x^2

Answer 34

I'm still confused..