ShmoopTube

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Slopes of parallel and perpendicular lines, a la Shmoop. [title page]

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Two magician's apprentices have turned their master into a bear--which is a problem, because [magician turns into bear]

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he's an angry bear. [bear chases kids]

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Help them figure out what went wrong by calculating whether the slopes of their magic rays were

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parallel or perpendicular.

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The equations of their magic rays are: y=3x+4 and y=3x+10. [equations shown]

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Fortunately, these equations are already set up in slope-intercept form (y=mx+b, where [equations on slopes]

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m is the slope). [slope-intercept form demonstrated]

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That means that the slope in each equation is 3.

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According to the Magician's Apprentice Handbook, "If two lines are perpendicular, their slopes [handbook opens]

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are negative reciprocals of each other."

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Negative reciprocals, when multiplied together, equal -1. [negative reciprocals defined]

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3 x -1/3 = -1, so if one of the two equations had a slope of -1/3, then these two equations

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would be perpendicular to each other. [perpendicular lines explained]

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If two lines are parallel, their slopes are the same. [parallel lines defined]

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Since we know each equation has a slope of 3, their slopes are parallel.

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Oh, here it is, page 32... [handbook opens]

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"Parallel magic rays deployed at the same time result in... bear."

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Magical antidote?

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Get rid of the evidence. [kids run from bear]

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