How to evaluate the sum of two functions

The teacher addresses a student's question by explaining how to handle functions and their inputs. The explanation includes identifying the domain of a function, changing input values, and performing function addition. A specific example is provided to illustrate the process, concluding with a confirmation of understanding.

What happens to the input value when you change it in a function?

How do you identify the domain of a function?

Explain the process of calculating F + G of X when the input is changed.

What is the result of the equation 4^2 + 1 + sqrt(4)?

How do you interpret the final answer of 19 in the context of the function discussed?