Math Chapter Wise Tangent, Normal, Increasing, Decreasing And Maxima/Minima Of A Function Of One Variable English MCQ UP PCS (Pre) 2008 Q.The necessary condition for a maximum or a minimum of a function f(x) is Adf 0 dx ≠ B2 d f ve dx = + C2 d f ve dx = − Ddf 0 dx = Show answer Correct answer: df 0 dx =