The function which is considered as function of values of another function is classified as

The function you are referring to is known as a composite function. In mathematics, a composite function is formed when one function is applied to the result of another function. This is often denoted as $(f \circ g)(x) = f(g(x))$, where $f$ and $g$ are two functions.

Composite functions are significant because they allow us to build more complex functions by combining simpler ones. For example, if you have a function $g(x)$ that transforms $x$ in a certain way, and then you have another function $f(y)$ that acts upon the result of $g(x)$, you can create a new function that gives us $f(g(x))$.

Understanding how to work with composite functions is crucial in calculus and in various applications across different fields of study, as they reflect how different processes or transformations can be layered together.