Function Notation and Linear Functions
Key Questions
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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)y=mx+b Where
color(red)(m)m is the slope andcolor(blue)(b)b is the y-intercept value.Then switch out the
yy variable forf(x)f(x) :f(x) = mx + bf(x)=mx+b -
Answer:
A function is a set of ordered pairs (points) formed from a defining equation, where, for each
xx -value there is only oneyy -value.Explanation:
x-------> yx−−−−−−→y represents a functionThis means that you can choose an
xx -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 andx_2 , you have that the fraction{f(x_1)-f(x_2)}/{x_1-x_2} is constant for every choice ofx_1 andx_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 somea andb \in \mathbb{R} .
Questions
Graphs of Linear Equations and Functions
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Graphs in the Coordinate Plane
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Graphs of Linear Equations
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Horizontal and Vertical Line Graphs
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Applications of Linear Graphs
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Intercepts by Substitution
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Intercepts and the Cover-Up Method
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Slope
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Rates of Change
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Slope-Intercept Form
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Graphs Using Slope-Intercept Form
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Direct Variation
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Applications Using Direct Variation
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Function Notation and Linear Functions
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Graphs of Linear Functions
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Problem Solving with Linear Graphs