MTH 100 Function Notation Objectives 1. Evaluate Functions. 2. Graph Simple Functions by Plotting Points. Objective 1 • We use “f(x)” to indicate the concept of a function. This expression is read as “f of x”. • To evaluate a function, substitute a value (from the domain) into the function rule. Simplify the expression; the resulting value is part of the range. Objective 1 Examples • Let f(x) = 4x – 5 and g(t) = 3t2 – 2t + 1. Find each of the following: 1. f(3) 2. g(-1) 3. f(a + 4) Objective 2 • IMPORTANT RULE: the point (a, b) lies on the graph of a function f if f(a) = b. • TRANSLATION: when you evaluate a function, the input is the x-coordinate and the output is the y-coordinate of a point on the function graph. • This is essentially the same as completing ordered pairs, or a table of values.