Determine which two equations represent perpendicular lines.

Question

(a) y = 3x – 6


(b) y = 1/3x + 6


(c) y = –1/3x + 6


(d) y = 1/3x – 6



Determine which two equations represent parallel lines.

(a) y = –4x + 2


(b) y = 4x + 2


(c) y = 1/2x + 2


(d) y = –4x + 6

Answer 1

for question 1 a and b represent perpendicular lines because perpendicular lines always have the same equation but only with the negative reciprocals for example
y=3x-6 is the negative reciprocal for y=-1/3+6 where you change the signs and flip the slope over example 3x changes to -1/3x