Linear Function

Definition:

A linear function is a polynomial of degree one.  The graph of a linear function is a straight line.  The rate of change of a linear function is called the slope of the function.  In a linear function, the average and instantaneous rate of change are always the same.  

Formula for a Linear Function:

Linear Function Photo:

Mr. Lee's Example Photo

Photo Description: This is a picture of the Chapel Bridge in Lucern, Switzerland that I took while on vacation.  The roof of this footbridge, originally constructed in 1333, can be modeled by a linear function.  I set the origin at the base of the stone tower.  Given this somewhat arbitrary origin, the roof of the bridge could be modeled by the function y = 0.25x + 2.