Writing+Linear+Functions-Target+A-Write+Me+a+Line-Guided+Learning

**Writing Linear Functions Target A: Write a linear function in Point slope form, Slope intercept form (function form) and Standard form. **

 * [[image:Discuss this.png width="173" height="97"]] || ==== Jeanette thinks that writing an equation of a line in slope intecept form (y=mx+b) is the only way to write an equation. ====

Whom do you agree with and why?
||

There are three different forms that can be used to write a linear function. The three forms are: function form (slope-intercept), point-slope form, and standard form. There are certain pieces of information that are needed to write a function in each of the three forms.

When writing a function in slope-intercept form, we use the equation y = mx + b, where m represents the slope, and b represents the y-intercept. So the two pieces of information needed to write a linear equation in slope-intercept form are the slope and the y-intercept. Sometimes these pieces of information are easily identified, other times these pieces might require a little more work to find. For example, if you were given the graph below, you can use the graph itself to identify the slope (rise over run) and y-intercept (where the line crosses the y-axis) in order to write the equation of the line that is represented by the graph. Since the slope is 2 and the y-intercept is located at (0, -4), the equation of the line in the graph would be written as y = 2x - 4 or f(x) = 2x - 4. We simply substituted the 2 for m and the -4 for the b value. But what if you are not given a graph? How would you write a linear equation in slope-intercept form? Take a look at the video below! media type="custom" key="26300592"
 * Slope-Intercept Form (Function Form) **

media type="custom" key="29348775"
 * You can also write a linear function in slope-intercept (function) form by first writing an equation in point-slope form and then CONVERTING the equation into slope-intercept form. Watch the video below for an example using the same points as the video above.**

Point-Slope Form math y-y_{1}=m(x-x_{1})\ math where //m// represents the slope and //(x 1, y 1 )// represent a point on the line. The appropriate mathematical way of saying x1 in the equation above is "x sub 1", but sometimes we just say "x one". To see how to write an equation in point-slope form, watch this video. media type="custom" key="26300602" Standard Form The general equation for standard form is: math Ax+By=C\ math When writing an equation in standard form, the x-term and y-term are on the same side of the equal sign, and the constant term is on the other. Learn how to write a linear equation in standard form by watching the video below: media type="custom" key="26300604"
 * In order to write a linear equation in point-slope form, you need to just that....a point and the slope! Once you have these two pieces of information, you want to write the equation using the point-slope equation: **

Why write an equation in standard form? Take a look at Writing Linear Functions Target B Guided Learning! Writing Linear Functions-Target A-Write Me a Line-Quick Check:** 1) Write an equation of a line in function form that passes through the points (6, -2) and (4, -8). 2) Write an equation using each of the three forms of the line that represents the graph. 3) Write an equation of a line in standard form that has a slope of 1/3 and passes through the point (-9, 5). Writing Linear Functions- Target A-Write Me a Line-Quick Check Solutions