Simplify the Composition of Two Functions

The video tutorial explains how to compose functions by plugging H of X into K of X. It covers the simplification of expressions under a radical and emphasizes the importance of not multiplying numbers outside and inside the radical. The tutorial concludes with determining the domain of the function, using inequalities and a number line to illustrate that X must be greater than or equal to -2.

What is the domain of the function as discussed in the text?

Explain the significance of the number line in determining the domain of the function.