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)

2 answers:

6 0

Table

x         f(x)

-2        0.2

-1        0.4

0         0.8

1         1.6

2          3.2

Look that the pair of data (0, 0.8), it means 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.

You have to replace the values of x in the equations and compare the results.

For f(x) = 0.8 * (2^x) 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 these results are the same of the table of the question, so the function is f(x) = 0.8 (2^x).

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