Suppose a parabola has its vertex at (0, 1) and its zeros at x = -3 and x = 3. Then equals _____.

A. 9-x^2

B. 1-1/9x^2

C. x^2-1

D. x^2-9

2 answers

vertex at (0,1) means y = -ax^2 + 1 where a>0.

since y=0 when x=3, we have

y = -1/9 x^2 + 1

(B)
B. Y = 1-(1/9)x^2 = 1 - x^2/9.
V(0,1).
When Xv = 0,
Y = 1-0/9 = 1.

When X = -3,
Y = 1 - (-3)^2 / 9 = 1--1 = o.

When X = 3,
Y = 1- 3^2 / 9 = 1 - 1 = 0.

Choice B satisfies all requirements.
Therefore,the answer is B.