Question

Which function does NOT represent exponential growth?

y= 3(0.2)^x

y= 3(2)^x

y= 0.3(2)^x

y=0.2(3)^x

Answer 1

When a decimal is multiplied to a power, it decreases exponentially. Therefore, y=3(0.2)^x does NOT represent exponential growth.

Answer 2

`y=2(0.2)^x`

Explanation:

Since, an exponential function is,

`f(x)=ab^x`

It has exponential growth if b > 1

And, it has exponential decay if 0 < b < 1,

In
`y=3(0.2)^x`

0 < 0.2 < 1

`y=3(0.2)^x` does not represent exponential growth.

In
`y= 3(2)^x`

2 > 1

`y= 3(2)^x` represents exponential growth.

In
`y= 0.3(2)^x`

2 > 1

`y= 0.3(2)^x` represents exponential growth.

In
`y=0.2(3)^x`

3 > 1

`y=0.2(3)^x` represents exponential growth.