MHT CET202020 Oct 2020Evening ShiftMathematicsPair of LinesActual
The joint equation of pair of lines through the origin and making equilateral triangle with the line y=4 is
Options
- A3 x²+y²=0
- B3 x²-y²=0
- Cx²-y²=0
- Dx²-3 y²=0
Correct answer
B. 3 x²-y²=0
Step-by-step solution
Let L ₁ and L ₂ be the required lines. Since OAB is equilateral, m ABO =60^ = m BAO Slope of line L ₂= 60^ = 3 and Slope of line L₁= ( -60^ )=- 3 Hence required equation is (y- 3 x)(y+ 3 x)=0 i.e. y²-3 x²=0 3 x²-y²=0