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Equation of a Line. Wednesday. Wayward Wednesday. Why is the sky blue? . Slope. Slope = . r ise run. We call slope the variable m. Y-intercept. The y-intercept occurs where x = 0. We call the y-intercept b. Equation of a Line. y = m x + b. slope. y-intercept. Equation of a Line.
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Equation of a Line Wednesday
Wayward Wednesday • Why is the sky blue?
Slope Slope = rise run We call slope the variable m
Y-intercept The y-intercept occurs where x = 0 We call the y-intercept b
Equation of a Line y = mx + b slope y-intercept
Equation of a Line Graph: y = ½x + 3 slope y-intercept
Equation of a Line Graph: y = ½x + 3 slope y-intercept
Equation of a Line Graph: y = –2x + 5 slope y-intercept
Equation of a Line Graph: y = –2x + 5 slope y-intercept
Equation of a Line Find the equation: y = mx + b slope y-intercept
Equation of a Line Find the equation: y = –1x + 3 slope y-intercept
Equation of a Line Find the equation: y = mx + b slope y-intercept
Equation of a Line Find the equation: y = 2x – 2 slope y-intercept
Equation of a Line Find the equation: y = mx + b slope y-intercept
Equation of a Line Find the equation: y = (2/3)x + 0 slope y-intercept
Finding the Equation of a Line • All you ever need is two unique pieces of information to figure out the equation of a line. Example: Let’s say you know the slope is ¾ and the y-intercept is ½. Then the equation of the line is: y = mx + b
Finding the Equation of a Line • All you ever need is two unique pieces of information to figure out the equation of a line. Example: Let’s say you know the slope is ¾ and the y-intercept is –½. Then the equation of the line is: y = ¾x –½
Finding the Equation of a Line • All you ever need is two unique pieces of information to figure out the equation of a line. Example: Let’s say the slope is 2 and a point on the line is (3, 7) y = mx + b
Finding the Equation of a Line • All you ever need is two unique pieces of information to figure out the equation of a line. Example: Let’s say the slope is 2 and a point on the line is (3, 7) y = 2x + b
Finding the Equation of a Line Example: Let’s say the slope is 2 and a point on the line is (3, 7) (7) = 2(3) + b 7 = 6 + b 7– 6 = b b = 1
Finding the Equation of a Line Example: Let’s say the slope is 2 and a point on the line is (3, 7) y = 2x + 1
Finding the Equation of a Line Example: Let’s say the y-intercept is (0, -4) and a point on the line is (2, -9) y = mx + b
Finding the Equation of a Line Example: Let’s say the y-intercept is (0, -4) and a point on the line is (2, -9) y = mx – 4
Finding the Equation of a Line Example: Let’s say the y-intercept is (0, -4) and a point on the line is (2, -9) (-9) = m(2) – 4 –9 + 4 = m(2) –5/2 = m
Finding the Equation of a Line Example: Let’s say the y-intercept is (0, -4) and a point on the line is (2, -9) y = (–5/2)x – 4
Finding the Equation of a Line Example: Let’s say we know that the line goes through the points (1, 2) and (3, 8) y = mx + b
Finding the Equation of a Line Example: Let’s say we know that the line goes through the points (1, 2) and (3, 8) y = mx + b Rise Run 8 – 2 3 – 1 6 2 m = = = = 3
Finding the Equation of a Line Example: Let’s say we know that the line goes through the points (1, 2) and (3, 8) y = 3x + b
Finding the Equation of a Line Example: Let’s say we know that the line goes through the points (1, 2) and (3, 8) (2) = 3(1)+ b 2 – 3 = b –1 = b
Finding the Equation of a Line Example: Let’s say we know that the line goes through the points (1, 2) and (3, 8) y = 3x – 1
Graph this line! slope = 2 y-intercept = -1
Graph this line! slope = -3 y-intercept = 2
Graph this line! y = 2x – 3
Graph this line! y = x + ½
Graph this line! y = -½x + 3
Graph this line! y = -3x + 2
Graph this line! y – ¼x – 3 = 0 y = ¼x + 3
Graph this line! 2y + 6x = 2 y = -3x + 1
Graph this line! ½y – x + 2 = 0 y = 2x – 4
Homework Page 418 #1 – 8 Page 419 #46 – 55