Multiple choice

If the quadratic equation 3x2 - 12x + 4k = 0 has equal roots, then the value of k is

  1. 1 3

  2. 12

  3. 3

  4. 2

  5. -3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Equal roots require the discriminant to be zero. Thus (-12)² - 4(3)(4k) = 0, so 144 - 48k = 0 and k = 3.

AI explanation

For a quadratic equation ax2 + bx + c = 0 to have equal roots, the discriminant must equal zero (b2 - 4ac = 0). Substituting a = 3, b = -12 and c = 4k gives (-12)2 - 4(3)(4k) = 0, which simplifies to 144 - 48k = 0. Solving for k gives 48k = 144, so k = 3.

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