Function Notation and Linear Functions
Key Questions
-
First, convert the linear equation to slope-intercept form. The slope-intercept form of a linear equation is:
#y = color(red)(m)x + color(blue)(b)# Where
#color(red)(m)# is the slope and#color(blue)(b)# is the y-intercept value.Then switch out the
#y# variable for#f(x)# :#f(x) = mx + b# -
Answer:
A function is a set of ordered pairs (points) formed from a defining equation, where, for each
#x# -value there is only one#y# -value.Explanation:
#x-------> y# represents a functionThis means that you can choose an
#x# -value and plug it into an equation, usually given as:#y= ....." " or" " f(x)= .....# This will give you a
#y# -value.In a function there will be only ONE possible answer for
#y# .If you find you have a choice, then the equation does not represent a function.
The following are functions:
#y=-3# #y=3x-5# #y = 2x^2-3x+1# #(1,2), (2,2), (3,2),(4,2)# The following are NOT functions:
#x= 3# #y=+-sqrt(x+20)# -
We can do more than giving an example of a linear equation: we can give the expression of every possible linear function.
A function is said to be linear if the dipendent and the indipendent variable grow with constant ratio. So, if you take two numbers
#x_1# and#x_2# , you have that the fraction#{f(x_1)-f(x_2)}/{x_1-x_2}# is constant for every choice of#x_1# and#x_2# . This means that the slope of the function is constant, and thus the graph is a line.The equation of a line, in function notation, is given by
#y=ax+b# , for some#a# and#b \in \mathbb{R}# .
Questions
Graphs of Linear Equations and Functions
-
Graphs in the Coordinate Plane
-
Graphs of Linear Equations
-
Horizontal and Vertical Line Graphs
-
Applications of Linear Graphs
-
Intercepts by Substitution
-
Intercepts and the Cover-Up Method
-
Slope
-
Rates of Change
-
Slope-Intercept Form
-
Graphs Using Slope-Intercept Form
-
Direct Variation
-
Applications Using Direct Variation
-
Function Notation and Linear Functions
-
Graphs of Linear Functions
-
Problem Solving with Linear Graphs