A polynomial of least possible degree has x-intercepts at and

MATHEMATICS · Single correct · AP · AP Precalculus · Polynomial and Rational Functions · Polynomial and Rational Functions

Problem

A polynomial of least possible degree has x-intercepts at

x=-3

and

x=3

, is symmetric about the y-axis, and passes through the point

(0,18)

. Which of the following is its equation? (a)

f(x)=x^{2}-18

(b)

f(x)=2\,(x^{2}-9)

(c)

f(x)=-2\,(x^{2}-9)

(d)

f(x)=-\dfrac{1}{2}\,(x^{2}-9)