Question

For which set of lines is it reasonable to state that the two lines are almost perpendicular to each other?

a. y = 2.1x 3, y = 2.1x 5
b. y = 0.9x 5, y = -1.26x 8
c. y = 5x 1.25, y = -5x 1.25
d. y = 3/4x 0.28, y = 4/3x 0.29

Answer 1

when you multiply their slopes and it gets to -1
y=mx+b

m=slope


A. 2.1*2.1=4.41
B. 0.9*-1.26=-1.134
C. 5*-5=-25
D. 3/4 times 3/4=1


B is answer