Question

If the lines y = 3x + 7 and 2y + px = 3 are perpendicular to each other, find the value of p.

Answer 1

y = 3x + 7

Slope of this line = 3

2y + px = 3

2y = −px + 3

`y = -(px)/2 + 3/2`

Slope of this line = `-p/2`

Since, the lines are perpendicular to each other, the product of their slopes is –1.

∴ `(3)(-p/2) = -1`

`(-3p)/2 = -1`

`p = 2/3`