Is the relationship between the variables in the table direct variation, inverse variation, both, or neither? If it is a direct or inverse variation, write a function to follow it.

Question

X:2 5 20 40
Y:40 20 5 2

ANSWERS AVAILABLE TO CHOSE:
A) NEITHER
B) INVERSE VARIATION Y=20/X
C)DIRECT VARIATION Y=20X
D) DIRECT VARIATION Y=X+15

Answer 1

well, is y/x constant?
40/2 is not 20/5

is xy constant?
2*40 is not 5*20

so, neither direct nor inverse.

of course, you could have just tried some values in the various choices to check them...

Answer 2

Ok so when I graphed it the inverse variation graph was the closest to the points shown, and shared the same "shape" as the points, however, the graph did not touch the points. Therefore, it is neither.