Math Chapter Wise Ordinary And Partial Differential Equations, Integral Equations And Calculus Of Variations English MCQ UP PCS (Pre) 2008 Q.Differential equation of the orthogonal trajectories of the family of parabolas y = ax2 is A2x y' y = B2x y' y = − Cx y' 2y = Dx y' 2y − = Show answer Correct answer: x y' 2y − =