JEE Main20208 Jan 2020Evening ShiftMathematicsParabolaActual
Let a line y = m x m > 0 , intersect the parabola, y 2 = x , at a point P , other than the origin. Let the tangent to it a P , meet the x -axis at the point Q . If area Δ O P Q = 4 square unit, then m is equal to
Correct answer
0
Step-by-step solution
Let the equation of tangent at P is 2 t y = x + t 2 So, Q - t 2 , 0 As given, area Δ O P Q = 4 square unit, so 1 2 0 0 1 t 2 t 1 - t 2 0 1 = ± 4 t 3 = ± 8 t = 2   t > 0 So, m = t t 2 = 1 2 .