Pair Of Straight Lines Question 36
Question: $ 2x^{2}+7xy+3y^{2}+8x+14y+\lambda =0 $ will represent a pair of straight lines, when $ \lambda $ =
[MP PET 1996]
Options:
A) 2
B) 4
C) 6
D) 8
Show Answer
Answer:
Correct Answer: D
Solution:
$ (2)(3)(\lambda )+2(7)(4)\frac{7}{2}-2{{(7)}^{2}}-3{{(4)}^{2}}-\lambda {{( \frac{7}{2} )}^{2}}=0 $
$ \Rightarrow 6\lambda +196-98-48-\frac{49\lambda }{4}=0\Rightarrow \lambda =8 $ .
BETA
