First of all, you have a small typo in your question. The actual question is: How do the graphs of the functions f(x) = (3/2)^x and g(x) = (2/3)^x compare?
g(x) = (2/3)^2 is not even a function :)
Notice that the base of g(x) is the base of f(x) inverted. Every time you see that pattern expect a reflection about the y-axis.
Let's check it out why.
There are two types of reflections in exponential function
- Reflection about the x-axis
To reflect an exponential function about the x-axis, multiply the output of the function by -1. For example, to reflect the function f(x)=e^x about the x-axis, we multiply the output, e^2, of function by -1 to get f(x)=-e^x.
- Reflection about the y-axis.
To reflect the exponential function about the y-axis, multiply the input of the function by -1. For example, to reflect the function f(x)=e^x, we multiply the input, x, of the function by -1 to get f(x)=e^-x.
Let's multiply the output our of function f(x) and see what happens:
Remember that according to the laws of exponents to get rid of the minus sign in the exponent we just need to flip the fraction:
Look! We just transformed f(x) into g(x)! Proving that they are reflections of each other over the y-axis.
We can conclude that the correct answer is the graphs are reflections of each other over the y-axis.