1. Sec. 1.3 – 1.4 Functions and Their Graphs
Ms. Zuniga
F239
IB Math Studies 1

2. I. Definitions
Relation: 2 quantities that are related to each other by some rule
Function: a relation that assigns to each element x in the set A exactly one element y in the set B

3. II. Mapping Domain: all x-values Range: all y-values
The relation is a function if the x-values don’t repeat
Ex.: (2,7), (4,6), (6,5), (8,6)

4. III. Function Notation f(x): “f of x”
ex 1. If f(x) = x2 – 1, find f(-1) and f(2)
Ex 2. If f(x) = x2 + 1, x<0
x – 1, x ≥0
Find f(-1)
f(0)
f(1)

5. IV. Find the domain of a function given its equation
Remember that in a fraction, the denominator cannot equal 0. So find what will make the denominator = 0.
Ex.1: f(x) = 1/(x2 – 4)
Ex. 2: g(x) = 1/(x+5)

6. Find the domain of a function given its equation
Remember that you can’t take the square root of a negative #; therefore, set whatever is INSIDE the radical sign greater than or equal to 0
Ex.1: h(x) = √(4 – x2)
Ex. 2: f(x) = 4x2 – 1

7. V. Vertical Line Test
Given a graph, you can determine whether it is a function or not by doing the vertical line test.
It’s NOT a function if the vertical line intersects the graph at more than one point

8. Vertical Line Test
Determine which of the following graphs are functions using the vertical line test

9. VI. Domain and Range of a Function
Determine the domain and range of the following function.