Answer:
Option A:
y = 3*(x - 5)^2 - 4
Step-by-step explanation:
For a quadratic equation:
y = a*x^2 + b*x + c
with the vertex (h, k), we can rewrite the function as:
such that:
h = -b/2*a
y = a*(x - h)^2 + k
Here we have the function:
y = 3*x^2 - 30*x + 71
the x-value of the vertex will be:
h = -(-30)/(2*3) = 30/6 = 5
And k is given by:
k = y(5) = 3*(5)^2 - 30*5 + 71 = -4
Then the vertex is:
(5, - 4)
And we can rewrite the equation in the vertex form as:
y = 3*(x - 5)^2 + (-4)
y = 3*(x - 5)^2 - 4
Then the correct option is A.