I was reading some book which had this question:
Q. The number of [quadratic] polynomials having zeros $-2$ and $5$ is:
(A) 1
(B) 2
(C) 3
(D) More than three?Sol. (A) 1.
But according to me there should be an infinite amount of polynomials. All these polynomials have the zeroes $-2$ and $5$:
\begin{align*}
(x+2)(x-5)&=0,\\
2(x+2)(x-5)&=0,\\
3(x+2)(x-5)&=0,\\
4(x+2)(x-5)&=0,\\
5(x+2)(x-5)&=0, \text{etc}.
\end{align*}
According to me, if we are given the two zeroes of a quadratic polynomial, then we can find $\infty$ polynomials with those two zeroes. I do not know why the answer $1$ is given in the book. Maybe it is a misprint? So am I right or the book is right?
Clarification: I just wanted to ask if these polynomials are considered to be the same or different.
Best Answer
You are right, the book is mistaken (perhaps they are taking polynomials which are constant multiples of each other as equal).