In this section, you'll learn how to add certain functions. First, we'll learn how to graphically add two piecewise linear functions, whose turning points occur at the same \(x\) positions. Then we'll learn how to add two linear functions, both graphically and algebraically. Finally, we'll learn how to add a linear and quadratic function, both graphically and algebraically. Before attempting this section, you should be excellent at reading coordinates from a graph, and you should be very good at combining like terms after distributing.