Answer:
y = (x-2)²/3 - 3
Explanation:
the vertex is at (2,-3), so the vertex form of the function is
y = A(x-2)²-3
where A is a constant to be found.
We see that when x=5, y=0, so substitute values to find A.
0 = A(5-2)² - 3
solve for A to get
A(3²) = 3
A = 1/3
So the equation is
y = (x-2)²/3 - 3
Check for x = -1
y = (-1-2)²/3 - 3 = 0 checks