Answer with explanation:
The Polynomial single variable function having highest degree of variable equal to 8, has 8 roots.for example

It must be kept in mind
Imaginary and Irrational root occur in pairs.
So,if the function in single variable has 8 roots, the roots can be all real, or even number of real roots, as well as even number of imaginary or Irrational roots.The possible combination of roots are as follows:
All real, (6 real ,2 Imaginary ),(4 real ,4 imaginary),(2 real,6 imaginary),All Imaginary,(6 real ,2 Irrational ),(4 real ,4 Irrational ),(2 real,6 Irrational),All Irrational.