Question

Write the equation of a line perpendicular to y =
3
x-3 and whose y-intercept is (0,12).

Answer 1

y=-1/3x+12

Explanation:

The slope of a line that is perpendicular to another is the negative reciprocal of the first. The slope of the line is 3 so the negative reciprocal will be -1/3.

Using the point-slope formula we can solve for the equation of a line with a slope of -1/3 and a point of (0,12).

The point slope formula is

y-y1=m(x-x1).

y-12=-1/3(x-0) -------------->Distribute: y-12=-1/3x ---------------> Isolate the y by moving the 12 to the other side. y=-1/3x+12

Answer 2

y=1/3x+12

When writing an equation for a line that’s perpendicular, don’t forget to flip the slope to its reciprocal