Math Chapter Wise Tangent, Normal, Increasing, Decreasing And Maxima/Minima Of A Function Of One Variable English MCQ PGT 2002 Q.The straight line x+y=a will be tangent to the ellipse 2 2 x y 1 9 16 + = + = if a= A8 B±5 C±10 D±6 Show answer Correct answer: ±5