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.