Pair Of Straight Lines Question 17
Question: If the equation $ ax^{2}+by^{2}+cx+cy=0 $ represents a pair of straight lines, then
Options:
A) $ a(b+c)=0 $
B) $ b(c+a)=0 $
C) $ c(a+b)=0 $
D) $ a+b+c=0 $
Show Answer
Answer:
Correct Answer: C
Solution:
$ ab(0)+2( \frac{c}{2} )( \frac{c}{2} )(0)-a{{( \frac{c}{2} )}^{2}}-b{{( \frac{c}{2} )}^{2}}-0{{(0)}^{2}}=0 $
$ \Rightarrow ac^{2}+bc^{2}=0\ \ \Rightarrow c^{2}(a+b)=0 $
$ \Rightarrow c(a+b)=0 $ .
BETA
