What notation is used for adding functions?

The correct notation for adding functions is represented by (f + g)(x). In this notation, f and g are two functions, and the expression (f + g)(x) signifies the sum of these two functions evaluated at the value of x.

To break this down further, the expression indicates that for any input x, you will take the output of function f when x is input into it and the output of function g when the same x is input into it, and then simply add those two results together. This operation adheres to the concept of function addition where you combine the outputs of the individual functions for the same input value.

The notation serves to reinforce the idea that you are combining the functional outputs, which is a fundamental operation in algebra. This notation is distinct and clear in its meaning, effectively conveying the action of summing two functions.