Question

Which is the quadratic variation equation for the relationship?

y varies directly with x2 and y = 72 when x = 6.

Answer 1

A.
y = 12x


B.
y = 4x2


C.
y = x2 + 25


D.


y = 2x2

Answer 2

Varies directly means x=ky where k is some constant. So you plug in x and y to find k, then put k in.

Answer 3

6=k*72?

Answer 4

Good call. I didn't see the square

Answer 5

"y varies directly with x2"
means y = k x^2 (where k is the number you want to find)

they gave you x and y, plug in
so 72 = k (6^2) and solve for k

Answer 6

Yea, so k=2 right?

Answer 7

um yeah :)

Answer 8

so plug what you got for k back into
y = k x^2

Answer 9

@wolfe8 you confused meh dere >,<
I only just learned it kinda a month ago
direct is y = kx not x = ky

Answer 10

72=2*36?

Answer 11

mmm the plugging x and y part was temporary

just plug in k = 2
into y = (k) x^2

Answer 12

Lol sorry. I wasn't in math mode. I'm talking about coffee and tights.

Answer 13

0.o lol what
...
nvm, don't wanna know... 0.0

Answer 14

lol

Answer 15

y=(2)x^2?

Answer 16

yep :)

Answer 17

but that is not even a answer choice lol

Answer 18

yeah it is

Answer 19

Oh yea it is D :P

Answer 20

yup :P

Answer 21

Ty