Question

Which set of ordered pairs could be generated by an exponential function?

A. (1, 1) (2, 1/2) (3, 1/3) (4, 1/4)

B. (1, 1) (2, 1/4) (3, 1/9) (4 1/16)

C. (1, 1/2) (2, 1/4) (3, 1/8) (4, 1/16)

D. (1, 1/2) (2, 1/4) (3, 1/6) (4, 1/8)

Answer 1

the answer is C
y=2^-x

Answer 2

The correct answer is:

C. (1, 1/2) (2, 1/4) (3, 1/8) (4, 1/16)

Explanation:

In order to be an exponential function, the y-coordinates of each point should be multiplied by a constant to get the next y-coordinate.  For C, we multiply by 1/2:

1/2(1/2) = 1/4; 1/4(1/2) = 1/8; 1/8(1/2) = 1/16

This means it is an exponential function.