Question

If Q is the foot of the perpendicular of the point P(3, 6) on the line x - 2y + 4 = 0, then the equation of PQ is

• A. 2x + y + 12 = 0
• B. 2x + y = 12
• C. x + 2y = 12
• D. x + 2y + 12 = 0

Answer 1

The correct option is B

2x + y = 12

PQ is r to x - 2y + 4

$\Rightarrow$ slope of PQ = -2

P(3,6) is a point on PQ and its slope is -2

$\Rightarrow$ equation of PQ $\equiv$ Y - 6 = -2(X - 3)

$\Rightarrow$ Y - 6 = -2x + 6

$\Rightarrow$ 2x + y = 12