Given:
[tex]f^{-1}(f(x))=f(f^{-1}(x))=?[/tex]
To find:
The missing value.
Solution:
We have,
[tex]f^{-1}(f(x))=f(f^{-1}(x))=?[/tex] ...(i)
We know that, if [tex]f(x)[/tex] is a function and [tex]f^{-1}(x)[/tex] is its inverse function, then
[tex]f^{-1}(f(x))=f(f^{-1}(x))=x[/tex] ...(ii)
From (i) and (ii), we get
Missing value = [tex]x[/tex]
Therefore, the missing value is [tex]x[/tex], i.e., [tex]f^{-1}(f(x))=f(f^{-1}(x))=x[/tex].