7
QuizMultiple Choice

Polynomial Functions — Test

Question 7 • Algebra II

Three roots of a fifth degree polynomial function f of x are negative 2 , 2 , and 4 plus i Which statement describes the number and nature of all roots for this function?

Answer
A
f of x has two real roots and one imaginary root.
B
f of x has three real roots.
C
f of x has three real roots and two imaginary roots.
D
f of x has five real roots.

Explanation

For a polynomial with real coefficients, nonreal complex roots occur in conjugate pairs. Since 4 + i is a root, 4 − i must also be a root. Together with the given real roots −2 and 2, that accounts for four roots; the fifth root must be real. So the function has three real roots and two nonreal (imaginary) roots, which is choice B.

AI-written and checked against the verified answer.

Previous
Next