Question

PLEASE HELP!




Which relationship shows a quadratic variation?

Answer 1

@jim_thompson5910

Answer 2

Do you get it? @jim_thompson5910

Answer 3

yes but i see multiple answers

are you sure it doesn't say "which one is NOT a quadratic variation?"

Answer 4

well I see 3 options which do

Answer 5

oh nvm, i'm thinking quadratic regression...oops my bad

Answer 6

you're looking for something of the form

y = k*x^2

k is some constant

Answer 7

so what I recommend you do is go through each choice

for each choice, plug in each ordered pair and see if you get the same value of k each time. If you do, then you've found your answer

Answer 8

B

Answer 9

Right?

Answer 10

sounds like you're guessing

Answer 11

Nope

Answer 12

B is the only choice that's not even a quadratic...at all

it's linear

Answer 13

so B is the last option I would pick

Answer 14

It goes in a correct pattern 3 6 9 12

Answer 15

well choice B is linear, so those points do NOT fall on a parabola and aren't formed from a quadratic

Answer 16

let's focus on choice B


plug in the first column

y = k*x^2

3 = k*1^2 .. plug in x = 1 and y = 3

3 = k*1

k = 3

------------------------


plug in the second column

y = k*x^2

6 = k*2^2 .. plug in x = 2 and y = 6

6 = k*4

k = 6/4

k = 3/2

------------------------

notice how k is NOT the same and it has changed

Answer 17

ok

Answer 18

the fact that k has changed when we moved onto another ordered pair suggests that choice B is NOT modeled by quadratic variation

Answer 19

ok

Answer 20

But it doesnt say not modeled

Answer 21

@Hero help plz

Answer 22

@ganeshie8 please help Im confused

Answer 23

Do you get it @ganeshie8

Answer 24

u oly have two more options to check
test options A and D
one of them is ur answer

Answer 25

D

Answer 26

I tried it

Answer 27

let me show u A :-

let's focus on choice A


plug in the first column

y = k*x^2

2 = k*1^2 .. plug in x = 1 and y = 2

2 = k*1

k = 2

------------------------


plug in the second column

y = k*x^2

5 = k*2^2 .. plug in x = 2 and y = 5

5 = k*4

k = 5/4


------------------------

notice how k is NOT the same and it has changed

Answer 28

But is it correct?

Answer 29

good :) for D, did u get same k ?

Answer 30

if yes, then D is a quadratic variation
if not, its not a quadratic variation

:)

Answer 31

medal jim

Answer 32

yes I just did :D

Answer 33

nice :)