Question 5 • [INMT3] Integrated Math 3 Sem 1 (26-27)
A third-degree polynomial has three roots when counted with multiplicity. Since its coefficients are real and two roots are the real numbers −4 and 4, the remaining root must also be real: any nonreal roots of a real polynomial occur in conjugate pairs, which cannot fit as just one remaining root. Therefore, f(x) has three real roots.
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