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Black Book Advanced Problems in MathematicsMathematicsQuadratic Equation

For what least integral 'k' is the quadratic trinomial (k - 2)x^2 + 8x + (k + 4) is positive for all real values of x ?

Options

  1. Ak = 4
  2. Bk = 5
  3. Ck = 3
  4. Dk = 6 .

Correct answer

B. k = 5

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