Question

Write the equation for a line perpendicular to y=-3x+18 that goes through the point (-12,6)

Answer 1

Answer:

$y=\frac{1}{3} x -14$

Step-by-step explanation:

The equation of the line you will find should be in the form y =mx+c , where m is the gradient and c is the y intercept.

The gradient of a line that is perpendicular to a line [of a known gradient] is the negative reciprocal of the gradient of the first. i.e. if a is the known gradient and the perpendicular gradient is b, ab = -1. Therefore the -3b=-1 and b= 1/3

you can now write y = mx +c as y = 1/3x +c

As you have been given a coordinate, you can input these values into y= 1/3x + c

-12 = 1/3(6) +c

-12 - 2 = c

c = -14

hence the equation of the line is y= 1/3x -14