Manipal MET2013MathematicsStraight Lines
The pair of lines 3 x^2-4 x y+ 3 y^2=0 are rotated about the origin by 6 in the anticlockwise sense. The equation of the pair in the new position is
Options
- Ax^2- 3 x y=0
- Bx y- 3 y^2=0
- C3 x^2-x y=0
- DNone of the above
Correct answer
C. 3 x^2-x y=0
Step-by-step solution
The given equation of pair of straight lines can be rewritten as ( 3 x-y)(x- 3 y)=0 . Their separate equations are, y= 3 x and y= 1 3 x y= 60^ x and y= 30^ x-y= 90^ x and y= 60^ x x=0 and y= 3 x Combined equation in the new position is x( 3 x-y)=0 or 3 x^2-x y=0