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KCET2008MathematicsQuadratic Equation

The real root of the equation x³-6 x+9=0 is

Options

  1. A-6
  2. B-9
  3. C6
  4. D-3

Correct answer

D. -3

Step-by-step solution

Given, x³-6 x+9=0 (x+3) (x²-3 x+3 )=0 x =-3 or x ²-3 x +3=0 Now, Discriminant, D = 9-4 3 = -3 imaginary Hence, real roots of the given equation is x=-3

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