Question

the lines having slopes m1 and m2 are perpendicular to each other if and only if ?

Answer 1

Answer:

Perpendicular lines cross at a 90 degree angle. You can look at the equations of two lines in slope intercept form and tell if the lines are perpendicular. If the slopes of two lines are m1 and m2 and m1 = -1/m2, the lines are perpendicular.

Answer 2

Answer:

show that two lines with slope m1 and m2 and parallel if and only if m1=m2