If x\(^2\) + 4 = 0, then x ?
 

  • A 4
  • B -4
  • C 2
  • D -2
  • E None of the above
jamb 1978mathematics

The correct answer is E. None of the above

The equation \(x^2 + 4 = 0\) can be rewritten as \(x^2 = -4\). The solutions to this equation are complex numbers, because the square of a real number is always non-negative, and cannot be -4.

The solutions are \(x = \sqrt{-4} = \pm 2i\), where \(i\) is the imaginary unit with the property that \(i^2 = -1\).

So, the correct answer is None of the above*because all the options are real numbers.

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