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

Question

write the equation in slope intercept form of the line that passes through the given point and is in perpendicular form

 

Answer 1

The slopes of perpendicular lines are negative reciprocals of each other.  The slope of y = (1/3)x + 2 is 1/3, the coefficient of x.  So, the slope of the other line is -3.  

 

Equation of line ⊥ to y = (1/3)x + 2 has the form y = -3x + b.

 

Since  (-3, 1) is a point on the line, the point must satisfy the equation.   So, 1 = -3(-3) + b

                       1 = 9 + b

                       b = -8

 

Equation of line:  y = -3x - 8