Question

Which equation is a direct variation function?

A. y = x
B. y = x^2
C. y = 1/4 x + 2
D. y = 4

(can only choose one option)

Answer 1

Answer: Choice A

===================================================

Step-by-step explanation:

Direct variation equations are of the form y = kx

k = constant of variation

For choice A, we have k = 1 to lead to y = 1x or simply y = x.

This is why choice A is the answer.

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

Choice B is ruled out because it's not linear.

Choice C is ruled out because the y intercept is not 0. All direct variation equations go through the origin.

Choice D is ruled out for the same reason as choice C.