Write an equation of the line that passes through the given point and is perpendicular to the graph of the given equation

Question

(5,7);y=1/3x+2

Answer 1

(5,7);y=1/3x+2

 

The slope of this line is 1/3

The slope of the perpendicular line is -1/(1/3) = -3

y = -3x + b through (5,7)

 

7 = -3(5) + b

7 = -15 + b

b = 22

 

y = -3x + 22

Answer 2

Perpendicular lines have slopes that are recriprocals and opposite signs.

 

Your equation x + y = - 4

 

solved for y is...   y = - x -4  (this line has a slope of -1)

 

Your new line needs a slope of +1

 

y = x + b

 

Solve for b by plugging in x and y

 

-6 = 3 + b

 

- 9 = b   ANSWER: y = x - 9