Answer: [tex]g(x)=(3)^{-x}[/tex]
Step-by-step explanation:
We know that if a figure is reflected across y axis then its y coordinate remains same but the x coordinate changes its polarity.
i.e. the function [tex]f(x)[/tex] will become [tex]f(-x)[/tex] .
Now, the given function :[tex]f(x)=(3)^x[/tex]
Then , after reflection across y axis the new function will become:
[tex]g(x)=f(-x)=(3)^{-x}[/tex]