What is the equation of the line in slope-intercept form that passes through the point (-2, 4) and is perpendicular to the line y = -2x + 4?

Question

anonymous · Answer

to find the equation of a line we need either:

a) two points
or
b) a point and a slope

This problem gives us a point, (-2,4), but we don't have any information about a second point, so option a is out.  This means we need to find the slope, option b

We are told that the slope of our line is perpendicular to this line:

y = -2x + 4

whose slope is -2

to find a slope perpendicular to a given one, we need to take the negative reciprocal of the given one

which turns out to be 1/2

plugging the point and slope into the equation gives

4 = (1/2)*-2 + b

we then solve for b and we get the equation

y = (1/2)x + 5