Things to Remember about slope and graphing

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Slope of Horizontal Line

Zero

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Slope of Vertical Line

Undefined

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Equation of Vertical Line

x = a number (where it crosses x-axis)

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Equation of Horizontal Line

y = a number (where it crosses y-axis)

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Slope Intercept Form of Equation of Line

y = mx + b

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Standard Form of Equation of Line

Ax + By = C

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Point-Slope Form of Equation of LIne

y - y1 = m(x - x1)

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Slope Formula

m = (y2 - y1) / (x2 - x1)

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Letter that is y-intercept

b

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y-intercept

Point where line crosses y-axis (put in zero for x): (0,b)

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x-intercept

Point where line crosses x-axis (put in zero for y): (a,0)

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Words in word problem that mean slope

Rate of Change

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Direction of positive slope

Up to the right

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Direction of negative slope

Down to the right

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Slopes of parallel lines....

... are the same slope

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Slopes of perpendicular lines...

... have opposite reciprocal slope (one is +, one is - AND they are reciprocals)