01 Which quantity must be zero for a point on the graph of a polynomial to be called a zero (root) of the polynomial?
Answer and explanation
Correct answer: A. Value of the polynomial \(P(x)\)
Explanation: For a number \(x=a\) to be a root of a polynomial we must have \(P(a)=0\). Thus the value of the polynomial at that x must be zero, so option A is correct. The constant term (option D) may be zero in some polynomials but it is not a necessary condition (e.g. \(P(x)=x-1\) has constant term \(-1\) yet root at \(x=1\)). Coefficients or exponents being zero do not by themselves indicate a root. Exam tip: on the graph, roots are the x-intercepts where \(y=0\); read off x-coordinates of those intercepts.