Question

Which of the following equations is not exponential?

y = 1^x
y = (1/2)^x
y = -2^x

Answer 1

`y=1^x` is not exponential function.

A is correct

Explanation:

Given:
`y=ab^x`

We need to choose exponential equation. The property of exponential equation.

Possible value of b

If b>1 then exponential growth

If 0<b<1 then exponential decay

Option 1:
`y=1^x`

Compare with exponential equation

`1^x=ab^x`

`b\rightarrow 1`

It is not exponential function.

Option 2:
`y=((1)/(2))^x`

Compare with exponential equation

`((1)/(2))^x^x=ab^x`

`b\rightarrow (1)/(2)`

It is decay exponential function.

Option 3:
`y=-2^x`

Compare with exponential equation

`-2^x=ab^x`

`b\rightarrow 2`

It is Growth exponential function.

Hence,
`y=1^x` is not exponential function.

Answer 2

The equation which is not exponential is the first one: y = 1^x.
The reason for this is because 1 to the power of anything is still one, which means the equation is linear, and not exponential. The rest of these equations are indeed exponential.