Answer :

To simplify the expression [tex]\( f(f^{-1}(x)) \)[/tex], understand the relationship between a function [tex]\( f \)[/tex] and its inverse [tex]\( f^{-1} \)[/tex]. By definition:

- [tex]\( f^{-1}(x) \)[/tex] is the inverse function of [tex]\( f(x) \)[/tex].

This means:
- If you apply [tex]\( f^{-1} \)[/tex] to some value [tex]\( y \)[/tex], and then apply [tex]\( f \)[/tex] to the result, you should get back [tex]\( y \)[/tex]. Mathematically, this can be represented as:

[tex]\[ f(f^{-1}(y)) = y \][/tex]

In our specific question, we have the value [tex]\( x \)[/tex].

1. Apply the inverse function [tex]\( f^{-1} \)[/tex] to [tex]\( x \)[/tex]:
[tex]\[ z = f^{-1}(x) \][/tex]
Here, [tex]\( z \)[/tex] is the value such that [tex]\( f(z) = x \)[/tex].

2. Next, apply the function [tex]\( f \)[/tex] to the result [tex]\( z \)[/tex]:
[tex]\[ f(z) = f(f^{-1}(x)) \][/tex]
Since [tex]\( z \)[/tex] is the value such that [tex]\( f(z) = x \)[/tex], we know:
[tex]\[ f(f^{-1}(x)) = x \][/tex]

Hence, the simplified form of the expression [tex]\( f(f^{-1}(x)) \)[/tex] is:

[tex]\[ \boxed{x} \][/tex]