First slide

Pair of straight lines

Question

If $p x^{2} - y^{2} + 3 x + 11 y + q = 0$ represents a pair of perpendicular lines then (p,q)=

Moderate

A

$(- 1, - 14)$
B

$(- 1, 28)$
C

$(1, - 28)$
D

$(- 1, - 28)$

Solution

$a = p, 2 h = 0, b = - 1, 2 g = 3, 1 f = 11, c = q$
$a + b = 0 \Rightarrow p = 1$
$a b c + 2 f g h - a f^{2} - b g^{2} - c h^{2} = 0 \Rightarrow q = - 28$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

Doubts App

OR

SCAN ME

Doubts App

Doubts App