First slide

Pair of straight lines

Question

$T h e a n g l e b e t w e e n t h e p a i r o f l i n e s w h o s e c o m b i n e d e q u a t i o n i s 2 x^{2} + 5 x y + 3 y^{2} + 6 x + 7 y + 4 = 0 i s \cos^{- 1} (\frac{k}{\sqrt{26}}) t h e n k =$

Moderate

A

1
B

2
C

4
D

5

Solution

$\begin{array}{rcl} C o s θ & = & \frac{a + b}{\sqrt{{(a - b)}^{2} + 4 h^{2}}} \\ = & \frac{5}{\sqrt{1 + 25}} \\ = & \frac{5}{\sqrt{26}} \\ T h e r e f o r e, k & = & 5 \end{array}$

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