Answer: The value is 8.
Step-by-step explanation: Given function is
[tex]f(x)=\log_3(x+1).[/tex]
we are given to find the value of [tex]f^{-1}(2).[/tex]
Let us consider that
[tex]f(x)=y~~~~~\Rightarrow x=f^{-1}(y).[/tex]
So, we have
[tex]f(x)=\log_3(x+1)\\\\\Rightarrow y=\log_3(f^{-1}(y)+1)\\\\\Rightarrow 3^y=f^{-1}(y)+1\\\\\Rightarrow f^{-1}(y)=3^y-1.[/tex]
If y = 2, then we have
[tex]f^{-1}(2)=3^2-1=9-1=8.[/tex]
Thus, the required value is 8.