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What are the roots of the equation x^2 + 4 = 0?
A2 and -2
B2i and -2i
Ci and -i
D4i and -4i
Answer & Solution
Correct answer: B. 2i and -2i
x^2 = -4 gives x = plus or minus 2i, since (2i)^2 = -4.
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