AP EAMCET201920 Apr 2019Morning ShiftMathematicsPair of LinesActual
If each line of a pair of lines passing through origin is at a perpendicular distance of 4 units from the point ((3,4) ), then the equation of the pair of lines is
Options
- A(7 x^2+24 x y=0 )
- B(7 y^2+24 x y=0 )
- C(7 y^2-24 x y=0 )
- D(7 x^2-24 x y=0 )
Correct answer
B. (7 y^2+24 x y=0 )
Step-by-step solution
Let equation of line passes through origin having slope (m ) is (y-m x=0 ), according to given information ( gathered |4-3 m| 1+m^2 =4 16+9 m^2-24 m=16+16 m^2 7 m^2+24 m=0 m=0 or m=- 24 7 gathered ) so combined equation of required lines ( aligned & y (y+ 24 7 x ) =0 & 7 y^2+24 x y =0 aligned ) Hence, option (2) is correct.