slope intercept by pB9GwF8

VIEWS: 13 PAGES: 9

									             y = mx + b
• The equation is called the slope intercept form for
  a line.
• The graph of this equation is a straight line.
• The slope of the line is m.
• The line crosses the y-axis at b.
• The point where the line crosses the y-axis is
  called the y-intercept.
• The (x,y) coordinates for the y-intercept are (0,b)
              Y = mx+ b
• If your slope is positive the line will go up
  hill.
• If your slope is negative the line will go
  down hill.
• Remember we read from left to right.
• Also, the slope is the m value.
• Slope is RISE over RUN written as a
  fraction.
• If the m is a whole number put it over one
  to form a fraction.
             Types of lines
• 1. All lines are straight.
• 2. They can be horizontal, vertical, or
  diagonal.
Graphing lines using the equation
•   Identify the Y-intercept (b) and graph it on the
    y-axis with a point.
•   Identify what the slope is (m). Remember slope
    is rise over run.
•   From the point on the y-axis, if your slope is
    positive go up or if it is negative go down
    whatever the RISE is. Go over to the right for
    the run. Mark the spot with a point.
•   Draw a line thru those two points
              Y= 2/3 x + 3
• Go to the y-axis and draw a point at 3.
• From that point go up 2 units and over 3
  units. Draw a point.
• Draw a line thru those two points.
• That is how easy it is to graph lines.
               Y = -3x -1
• Go to the y-axis and draw a point at –1.
• From that point go down 3 units and over 1.
  Draw a point.
• Draw a line thru those points.
• Wow that was easy!
                   Y= 2

• Draw out a two column box. The first
  column is labeled X and the second column
  is labeled Y.
• Fill the Y column with values of 2 because
  the equation said so.
• Pick any values for x.
• Now graph those ordered pairs and draw a
  line thru those points.
                   X= -4
• Make a chart again like last time.
• But, All the values for x are –4’s. Because
  our equation said so.
• You decide the values for the y’s.
• Now graph the ordered pairs and draw a
  line thru those points.

								
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