Find the equation whose graph is a parabola with vertex $(2,4)$, vertical axis of symmetry, and contains the point $(1,1)$. Express your answer in the form "$ax^2+bx+c$".
Vertex form of parabola
y = a (x-2)^2 + 4 sub in the point 1,1 to calculat the value of 'a'
1 = a (-1)^2 + 4
-3 = a
y = -3 (x-2)^2 + 4
y = -3x^2 + 12x - 8
Vertex form of parabola
y = a (x-2)^2 + 4 sub in the point 1,1 to calculat the value of 'a'
1 = a (-1)^2 + 4
-3 = a
y = -3 (x-2)^2 + 4
y = -3x^2 + 12x - 8