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3. Write the equation of a line that is perpendicular to y= x/3 + 3 and goes through the point (-1,-2)

User Bvarga
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The equation of a line in the slope intercept form is expressed as

y = mx + c

where

m reresents slope

c represents y intercept

The equation of the given line is

y = x/3 + 3

By comparing both equations,

m = 1/3

recall, if two lines are perpendicular, it means that the slope of one line is the negative reciprocal of the slope of the other line. Recall, the negative reciprocal of 1/3 = - 3/1 = - 3 This means that the slope of the perpendicular line passing through the point (- 1, - 2) is

m = - 3

We would find the y intercept, c by substituting m = - 3, x = - 1 and y = - 2 into the slope intercept equation. We have

- 2 = - 3 * - 1 + c

- 2 = 3 + c

Subtracting 3 from both sides,

- 2 - 3 = 3 - 3 + c

c = - 5

By substituting m = - 3 and c = - 5 into the slope intercept equation, the equation of the perpendicular line is

y = - 3x - 5

User Ericgu
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