Math Trailhead

For any input  \(x\)  and functions  \(f\)  and  \(g\text{,}\)  this action defines a composite function, which we write as \(f \circ g\)  such that

\(\displaystyle{(f\circ g)(x) = f(g(x))}\)

The domain of the composite function  \(f\circ g\)  is all  \(x\)  such that  \(x\)  is in the domain of  \(g\)  and  \(g(x)\)  is in the domain of  \(f\text{.}\)