This document defines and provides examples of constant and linear functions. A constant function has values that do not vary, with examples given by y=5 and x=50. A linear function is a first degree polynomial of one variable in the form of y=mx+c, where m is the slope and c is the y-intercept. Linear functions are represented by straight lines that can be skewed left if m<0 or right if m>0. Examples of linear functions and their domains and ranges are given.

1. Mohd Noor Abdul Hamid, Ph.D

2. 1. CONSTANT FUNCTION
• a function whose values do not vary and thus are constant
Eg 1: y = 5
Domain = { x ε R }
-∞ +∞
5
Range = { y = 5 }

3. 1. CONSTANT FUNCTION
• a function whose values do not vary and thus are constant
Eg 2: x= 50
Domain = { x = 50 }
Range = { y ε R }
50
+∞
-∞

4. 2. LINEAR FUNCTION
• a first degree polynomial function of one variable
y = f(x) = mx + c
slope / gradient y-intercept
• graph : straight lines.
- skewed to the left  m < 0
- skewed to the right  m > 0

5. 2. LINEAR FUNCTION
Example 1 : y = 2x + 4
-∞ +∞
Domain = { x ε R }
+∞
-∞
Range = { y ε R }

6. 2. LINEAR FUNCTION
Example 1 : y = -5x + 10
-∞ +∞
Domain = { x ε R }
-∞
+∞
Range = { y = R }