Answer:
[tex]y=1^x[/tex] is not exponential function.
A is correct
Step-by-step explanation:
Given: [tex]y=ab^x[/tex]
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: [tex]y=1^x[/tex]
Compare with exponential equation
[tex]1^x=ab^x[/tex]
[tex]b\rightarrow 1[/tex]
It is not exponential function.
Option 2: [tex]y=(\frac{1}{2})^x[/tex]
Compare with exponential equation
[tex](\frac{1}{2})^x^x=ab^x[/tex]
[tex]b\rightarrow \frac{1}{2}[/tex]
It is decay exponential function.
Option 3: [tex]y=-2^x[/tex]
Compare with exponential equation
[tex]-2^x=ab^x[/tex]
[tex]b\rightarrow 2[/tex]
It is Growth exponential function.
Hence, [tex]y=1^x[/tex] is not exponential function.
