Question

$a x ^ { 2 } + 2 y ^ { 2 } + 2 b x y + 2 x - y + c = 0$ represents a circle through the origin, if.

• A. $a = 0 , b = 0 , c = 2$
• B. $a = 1 , b = 0 , c = 0$
• C. $a = 2 , b = 2 , c = 0$
• D. $a = 2 , b = 0 , c = 0$

Answer 1

Answer: (D)

$a = 2 , b = 0 , c = 0$

Answer 2

See condition for circle and also condition for circle to pass through origin i.e. origin satisfies equation of circle or $c = 0$ .