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How to find the slope of the perpendicular lines?

How to find the slope of the perpendicular lines?-example-1
User Amal Ts
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1 Answer

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The line going uphill as you read from left to right has a slope of 3/2

This is because you start at the point (-1,-1) and go up 3, then to the right 2

rise = 3

run = 2

slope = rise/run = 3/2

Following this pattern of "up 3, over to the right 2" and you'll land on the point (1,2)

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The line going downhill as you read from left to right has a slope of -2/3

There are two ways to get this answer.

Method 1: You can find the negative reciprocal of the first slope. So we flip the fraction 3/2 to get 2/3, then change from positive to negative to get -2/3

Method 2: Start at the point (-1,-1). Then move down 2 units and to the right 3 units to arrive at the point (2,-3). This shows that the slope is rise/run = -2/3

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side note: the two perpendicular slopes 3/2 and -2/3 multiply to -1.

User Grandchild
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