A function that can be graphically represented in the Cartesian coordinate plane by a straight line is called a Linear Function.

More About Linear Function

A linear function is a first degree polynomial of the form, F(x) = m x + c, where m and c are constants and x is a real variable.
The constant m is called slope and c is called y-intercept.

Example of Linear Function

y = 3x + 5 is a linear function.
The graph of the function y = 2x is shown below. This is a linear function since the points fit onto a straight line

Video Examples: Graphing Linear Functions by Finding X,Y Intercept

Solved Example on Linear Function

Ques: Identify the graph that represents a linear function.

Choices:

A. Graph 1
B. Graph 3
C. Graph 4
D. Graph 2

Correct Answer: C

Solution:

Step 1: The graph of a linear function is a straight line.
Step 2: Graph 4 is a straight line.
Step 3: So, Graph 4 represents a linear function.