"quadration?" "quadratic equation?"
Write out the general vertex form and then plug in the given info:
y = a(x-h)^2 + k
Vertex at (3,3): y = a(x-3)^2 + 3
curve passes thru (5,11): 11 = a(5-3)^2 + 3
11 = a(2)^2 + 3 = 4a + 3 = 11, or a = 2
Then the equation of this parabola is
y = 2(x-3)^2 + 3.
check: Does this pass thru (5,11)? Is 11 = 2(5-3)^2 + 3 true?
Is 11 = 2(4)+3 true? YES