Question

The slope of two lines are - 3/2 and 18/a. Determine the value of α that will make the lines:

a) parallel

b) perpendicular

Answer 1

a) a=-12

b) a=27

Explanation:

a) parallel lines have = slopes SO

-3/2 = -3/2

-3/2 = 18/a

-3a/2 = 18

-3a = 18 * 2 = 36

a = -12

b) perpendicular lines have negative inverse slopes SO

- 3/2 ---> 2/3

2/3 = 18/a

2a/3 = 18

2a = 18 * 3 = 54

a = 54/2 = 27