The real number K for which the equation is, 2x3 + 3x + k = 0 has Two distinct real roots in {0,1}

Answer from the following options – (a) lies between 1 and 2 (b) lies between 2 and 3 (c) lies between -1 and 0 (d) does not exist

Your Answer

Correct option will be (d)
f(x) = 2x3 + 3x + kf′(x) = 6x2 + 3f′(x) = 0
          ⇒ x2 = -1/2
          Not Possible.
          As condition for two distinct real root is f(α) f(β) = 0
         (where α, β are roots of f '(x) = 0 )

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