2.4 More About Linear Equations Notes.notebook
2.4 More About Linear Equations
September 11, 2013
Name: _______________
Objectives:
­F.IF.8: Write a function defined by an expression in different but equivalent forms.
­F.IF.9: Compare properties of two functions each represented in a different way.
The equation of the line in ______-______ ______ through the
point (x1,y1) with slope m:
Doesn't this look familiar? Solve the equation for m:
So, it's really just the ______ formula in disguise!
Sep 8­2:33 PM
Examples: Write the equation in slope-intercept form. Then graph.
1.) m = 2, passes through the point (-3,2)
2.) passes through the points (1,0) and (5,5)
Sep 8­2:44 PM
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2.4 More About Linear Equations Notes.notebook
Parallel Lines
September 11, 2013
Perpendicular Lines
Examples Write the equation of the line in slope-intercept form.
1.) Parallel to y = -3x + 1 and passes through (-3,4).
2.) Perpendicular to y = -3x + 1 and passes through (3,-1).
Sep 8­2:46 PM
3.) Parallel to 2x - 3y = -3 and passes through (-7,10).
4.) Perpendicular to 3x + y = 1 and passes through (-2,1).
Standard Form: Ax + By = C, where A, B and C are real numbers.
A and B cannot both be zero.
Sep 8­2:48 PM
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2.4 More About Linear Equations Notes.notebook
September 11, 2013
Examples: Write the equations in standard form.
1.) y = (3/4)x - 5
2.) y = 9.1x + 3.6
Remember x and y intercepts???
To find the x-intercept, set y = ___ and solve for ____.
To find the y-intercept, set x = ___ and solve for ____.
Sep 8­2:53 PM
3.) Graph 3x + 5y = 15 by finding the x and y-intercepts.
CONCEPT SUMMARY
Slope-intercept Form
y = mx + b
Use this form when
you know the slope
and the y-intercept.
Point-Slope Form
y - y1 =m(x - x1)
Use this form when you
know the slope and
a point, or when you
know two points.
Standard Form
Ax + By = C
Use this form
when you are
graphing by finding
intercepts.
Sep 8­2:55 PM
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2.4 More About Linear Equations Notes.notebook
September 11, 2013
Name: ________________
2.4 Homework
Write the equations of the lines in slope-intercept form. Write your
answers on the lines provided.
1.) m = 3, passes through (1,5)
1.) _____________
2.) passes through (-10,3) and (-2,-5)
2.) _____________
3.) parallel to y = (2/5)x - 3 and
passes through (1,-1).
3.) _____________
Sep 8­2:57 PM
4.) perpendicular to 3x - 4y = 16
and passes through (-3,2)
4.) ____________
5.) Write (1/2)y = -6x + 3 in
standard form.
5.) ____________
6.) Which form would you use to write the equation of a line if
you knew its slope and x-intercept? Explain.
7.) If the intercepts of a line are (a,0) and (0,b), what is the slope of the
line?
Sep 8­3:30 PM
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