If `l,m` are variable real numbers such that `5l^2+6m^2 -4lm+3l=0` and the variable line `l...

374 views · Published 12 October 2018 · 10:24 · Indexed 30 September 2026

Channel: Doubtnut · 2018 · Education

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To ask Unlimited Maths doubts download Doubtnut from - https://goo.gl/9WZjCW  If   `l,m` are variable real numbers such that  `5l^2+6m^2 -4lm+3l=0` and the variable line `lx + my = 1` always touches a fixed parabola  `P(x,y) = 0` whose axis parallel to x-axis , then A) vertex of P(x,y) is (-5/3, 4/3) B) Latus Rectum is equal to 4 C) Directrix of P(x,y) is parallel to y-axis (D) AB is a  focal chord of P(x,y) =0 then `1/(SA)+1/(SB)=1/2` where S is the focus

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