Pair Of Straight Lines Question 46
Question: If the equation $ Ax^{2}+2Bxy+Cy^{2}+Dx+Ey+F=0 $ represents a pair of straight lines, then $ B^{2}-AC $
[MP PET 1992]
Options:
A) < 0
B) = 0
C) > 0
D) None of these
Show Answer
Answer:
Correct Answer: D
Solution:
Using the condition $ \Delta =0 $
$ \Rightarrow ACF+2.\frac{E}{2}.\frac{D}{2}.B-A.{{( \frac{E}{2} )}^{2}}-C.{{( \frac{D}{2} )}^{2}}-F.{{(B)}^{2}}=0 $ .
BETA
