to do these, start by looking at the "b" value -6.
divide it by 2
-6/2 = -3
now square this number
(-3)^2 = 9
this is what you need for the "c" value
there is only a 5 for the c value so add 4 to both sides of the equation. ( +4 = +4)
y +4 = x^2 -6x +5 +4
y +4 = x^2 -6x +9
y +4 = (x -3)^2
y = (x -3)^2 - 4
vertex ( 3, -4) upwards facing like a bowl, because the "a" value is positive. So the vertex is the minimum, lowest point on the graph.
