Find the slope of any line perpendicular to
the line through point (6,3)and (7,7).
You need two things:
1. The slope formula
2. The fact that perpendicular lines have slopes
which are reciprocals but with the opposite sign.
1.
y2 - y1 (7) - (3) 4
m = --------- = ----------- = --- = 4
x2 - x1 (7) - (6) 1
2.
The slope of a line perpendicular to a line with
slope 4/1 is the reciprocal of 4/1 with the sign
changed. That is, it's
m = -1/4
Edwin
