Question

Variable y varies directly with x^2, and y = 48 when x = 4.

Which graph represents the quadratic variation?

Answer 1

A. http://static.k12.com/calms_media/media/1540000_1540500/1540310/1/e704306724d0e3058f5f975d02ad64262eb5d886/MS_ALG_S2_01_12_quiz_Q5a_question.gif

Answer 2

B. http://static.k12.com/calms_media/media/1540000_1540500/1540311/1/d3c9c95d917ce7280f5dbce58d52cc1b289e4903/MS_ALG_S2_01_12_quiz_Q5b_question.gif

Answer 3

C. http://static.k12.com/calms_media/media/1540000_1540500/1540312/1/520c64d5cf628a3b4b22b816792234a7675902b7/MS_ALG_S2_01_12_quiz_Q5c_question.gif

Answer 4

D. http://static.k12.com/calms_media/media/1540000_1540500/1540313/1/69f31c1a860fc344187f2804ec831319d4f09b69/MS_ALG_S2_01_12_quiz_Q5d_question.gif

Answer 5

Phew thanks for coming i really need help @geerky42

Answer 6

"Variable y varies directly with x^2, and y = 48 when x = 4"

So you are given \(y = kx^2\), where k is unknown.

Firstly you need to solve for k. Plug in y=48 and x=4.

\((48) = k(4)^2\)

Can you do that?

Answer 7

3?

Answer 8

@geerky42

Answer 9

@campbell_st

Answer 10

you have calculated k correctly so the equation is

\[y = 3x^2\]

Answer 11

I haven't looked at the choices...

but using the equation you can find some points it passes through

x: -2 : -1: 0 : 1 : 2
--------------------
y

then look at the choices and see if the parabola passes through them

hope it helps

Answer 12

So my answer is C then? @campbell_st

Answer 13

I just viewed and it does seem to match the table values

Answer 14

Ok thanks so much sorry that i didn't respond sooner os is running really slow