Pair Of Straight Lines Question 9
Question: The nature of straight lines represented by the equation $ 4x^{2}+12xy+9y^{2}=0 $ is
[MP PET 1988]
Options:
A) Real and coincident
B) Real and different
C) Imaginary and different
D) None of the above
Show Answer
Answer:
Correct Answer: A
Solution:
$ 4x^{2}+12xy+9y^{2}=0 $ .
Here $ h^{2}-ab=36-36=0 $ , $ ( from\tan \theta =\frac{\pm 2\sqrt{h^{2}-ab}}{a+b} ) $ .
Hence, lines are real and coincident.
BETA
