How do you start composing a mathematical function?

To start composing a mathematical function, first identify the two functions you wish to combine, typically denoted as ( f(x) ) and ( g(x) ). The composition of these functions is expressed as ( (f \circ g)(x) = f(g(x)) ), meaning you apply the function ( g ) to ( x ) first, and then apply the function ( f ) to the result of ( g(x) ). Ensure that the output of the inner function ( g(x) ) is within the domain of the outer function ( f ). Finally, simplify the resulting expression if possible.