Parallel and Perpendicular Lines

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Parallel and Perpendicular Lines

• By Lindsey Hyde

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Parallel Must keep same slope as in
equationPerpendicular Must have slope that is
an opposite reciprocal
Example Perpendicular lines Write an equation
of a line that passes through (4,5) and is
perpendicular to the line y2X3 STEP 1 Find
slope (always before/with X) Slope 2 2/1
(fraction form) opposite reciprocal -1/2 STEP
2 plug in slope and point into equation
(ymxb) -5 -1/2 4 b First multiply -1/2 and
4 -5-2B Get B by itself by getting rid of the
-2 and getting it to the other side (add positive
2 to both sides) -2 and 2 will cancel -5 /
2 -3B put into slope intercept form y-1/2x-3
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Parallel Lines

• Example Parallel lines
• Write and equation of the line passing through
  (-2,11) and is parallel to the line
• y-1x5 (keep same slope)
• 11-1-2b
• 112b
• 9B
• Put in slope intercept form
• Y-1x9

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Try this one yourself!

• Write and equation in slope-intercept form of the
  equation y3x5 and runs through the point (5,4).
  (parallel line)
• STEP ONE keep slope the same
• STEP TWO plug the point (5,4) into the equation
  (x,y)
• STEP THREE Multiply 3 and 5
• STEP FOUR get rid of the 15 by adding a negative
  15 to both sides of equation
• STEP FIVE B?

FINAL ANSWER
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• B-11