Question

A fifth-degree polynomial equation with rational coefficients has the roots 3, 8i, and 7- radical 5. Which are also roots of the polynomial equation?

Answer 1

Using complex numbers and radicals, it is found that the correct option is C.

When a complex number is a root of a polynomial function, it's conjugate also has to be.

• Hence, since 8i is a root of the function, -8i is also a root.

The same is valid for radicals, as they are in the $\pm$ format.

• Since $7 - \sqrt{5}$ is a root, $7 + \sqrt{5}$ is also a root.

Hence, option C is correct.

For more on complex numbers and radicals, you can check brainly.com/question/25173944