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Find all real and complex zeros of the polynomial, and write p(x) as the product of linear factors.
P(x)=x^4-9x^2+4x+12
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Apply grouping to factor P(x):
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So, one root is x = -3.
Next, transform and factor the polynomial Q(x) = x^3 - 3x^2 + 4.
Add and distract x^2 and then apply grouping, again:
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The roots of the polynomial Q(x) are -1, -2, 2.
Answer. The roots of the polynomial P(x) are -3, -2, -1, and 2.