Problem
Solution
For this case we know that the vertex is given by (3,6) and the genera equation for a parabola is given by:
y= a(x-h)^2 +k
Where h = 3, k=6 and replacing we have:
y= a(x-3)^2 +6
And we can find the value of a with the point given x= 4, y=4
4= a(4-3)^2 +6
4= a +6
a= 4-6=-2
And the correct equation would be:
d. y= -2(x-3)^2 +6