JEE Main2005MathematicsCircleActual
If the pair of lines a x^2+2(a+b) x y+b y^2=0 lie along diameters of a circle and divide the circle into four sectors such that the area of one of the sectors is thrice the area of another sector then
Options
- A3 a^2-10 a b+3 b^2=0
- B3 a^2-2 a b+3 b^2=0
- C3 a^2+10 a b+3 b^2=0
- D3 a^2+2 a b+3 b^2=0
Correct answer
D. 3 a^2+2 a b+3 b^2=0
Step-by-step solution
aligned & | 2 (a+b)^2-a b a+b |=1 & (a+b)^2=4 (a^2+b^2+a b ) & 3 a^2+3 b^2+2 a b=0 . aligned