Multiple choice

If the roots of the quadratic $2x^{2}+kx+2=0$ are equal then the value of $'k'$ is

  1. $4$
  2. $-4$
  3. $\pm 4$
  4. $\pm 16$
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C Correct answer
Explanation

For a quadratic equation ax^2 + bx + c = 0 to have equal roots, the discriminant D = b^2 - 4ac must be 0. Here, k^2 - 4(2)(2) = 0, so k^2 = 16, which means k = +/- 4.

AI explanation

The condition for a quadratic equation to have equal roots is that its discriminant equals zero. For the equation 2 x squared + k x + 2 = 0, the discriminant is k squared - 4(2)(2), which is k squared - 16. Setting this equal to zero gives k squared = 16, so the value of k is plus or minus 4.

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