How can you determine if the given lines are perpendicular :(a)(1,4) and (-1,1) (b) (3,3) and (-1,-1)
a. 4-1/-2-1 = 3-1/3-1
b. 4-1/-2-1 = 3-(-1)/3-1
c. 4-1/1-(-2)= 3-(-1)/3-(-1)
d. 1-(-2)/4-1 = 3-1/3-1
The slopes of perpendicular lines are
negative reciprocal of each other.
a. m1 = (1-4)/(-1-1) = -3/-2 = 3/2
b. m2 = (-1-3)/(-1-3) = -4/-2 = 2
The 2 lines are not perpendicular.
Note: If the slope of the 2nd line was
-(2/3), the lines would be perpendicular.