Question

# Are lines L1 and L2 perpendicular: L1 (-7,1) and (5,-2) L2 (3,7) and (0,-5) a.) No,...

Are lines L1 and L2 perpendicular: L1 (-7,1) and (5,-2) L2 (3,7) and (0,-5) a.) No, the lines are not perpendicular because the product of their slope equals -1. B.) Yes , the lines are perpendicular because the product of their slopes does not equal -1. C.) No, the lines are not perpendicular because the product of their slopes does not equal -1. D.) Yes, the lines are perpendicular because the product of their slope equals -1.

The given lines are L1 (-7,1) and (5,-2) L2 (3,7) and (0,-5)

WE know that slope of a line passing through two points (x1,y1) and (x2,y2) is

m=(y2-y1)/(x2-x1)

The line L1 through two points (-7,1) and (5,-2)

So the slope is m1=(-2-1)/(5-(-7))

= (-3)/12

= -1/4

The line L2 is through points (3,7) and (0,-5) so the slope is

m2 = (-5-7)/(0-3) = (-12)/(-3)

= 4

Since m1* m2 = (-1/4)*4

=-1

So the lines are perpendicular as the product of their slope is -1

Therefore option D is correct