The key piece of information for these questions is the Fundamental Theorem of Algebra, which states that a degree n polynomial has n complex roots. A complex root can be either real or imaginary.
First question, regarding the polynomial y = x^3 - 3x^2 + 16x - 48: We know there is one real root, the x-intercept. Since it's a third degree polynomial, there are three complex roots in total. Therefore, there is one real root and two imaginary roots. Answer is B
Second question: You probably can guess the answer, now that you know the Fundamental Theorem of Alegebra: There are 3 real zeros, each with multiplicity one, meaning each root only happens once. It's a 5th degree polynomial, so there are a total of 5 roots, implying 2 imaginary roots.
Using the cosine rule we can work out the length of the side opposite the indicated right angle which came to be 15mm then the final answer came to be 163mm^2
