Question 1013017
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Solve: x^4 -3x^2 =4 (find 4 roots)
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<pre>
{{{x^4 - 3x^2 -4}}} = {{{0}}},

Factor left side. You will get

{{{(x^2-4)*(x^2+1)}}} = {{{0}}}.

The roots are 2, -2, i and -i.
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