Question

The equation of line AB is (y − 3) = 5 (x − 4). What is the slope of a line perpendicular to line AB? (4 points) −5 5 negative 1 over 5 1 over 5

Answer 1

-1/5

Explanation:

(y - 3) = 5(x - 4)

this is point slope form : (y - y1) = m(x - x1)......and in this form, the slope is in the m position. So this line has a slope of 5. A perpendicular line will have a negative reciprocal slope. All that means is " flip " the slope and change the sign.

5 or 5/1.....flip it.....1/5.....change the sign...-1/5.

so a perpendicular line will have a slope of -1/5