Which exponential function is represented by the table? f (x) = 2 (2x) f (x) = 0.8 (0.8x) f (x) = 2 (0.8x) f (x) = 0.8 (2x)

table

-2 0.2

-1 0.4

0 0.8

1 1.6

2 3.2

The answer is the last option, f (x) = 0.8 * (2^x)

The first strong indicator is that the fourth pair of data (0, 0.8) indicates that f (0) is 0.8

Given that a^0 = 1, means that the coefficient of the function has to be 0.8 and you discard the first and the third options, because for them two f (0) = 2.

AT the end what you have to do is to replace the values of x in equations and compare the results.

So, for the fourt opion you get:

x f (x) = 0.8 * (2^x)

-2 0.8 * (2^-2) = 0.8 / 4 = 0.2

-1 0.8 * (2^-1) = 0.8 / 2 = 0.4

0 0.8 * (2^0) = 0.8 * 1 = 0.8

1 0.8 * (2^1) = 0.8 * 2 = 1.6

2 0.8 * (2^2) = 0.8 * 4 = 3.2

As you can see this results are the same of the table of the question, so the function is f (x) = 0.8 (2^x).

I just took the test and the answer is D. f (x) = 0.8 (2^x)