If a polynomial function f(x) has roots –8, 1, and 6i, what must also be a root of f(x)? –6 –6i 6 – i 6

Second Option

Step-by-step explanation:

If a polynimial has an imaginary root of the form a + bi then it necessarily has another imaginary root (conjugate) of the form a-bi.

In this case, notice that the polynomial has the following imaginary root:

.

This can be written as:

In this case and .

Therefore the conjugate root is:

  or  

finally the answer is  

70.30

step-by-step explanation: