Do you mean f(x)=-3x2+18x-27?
If so, then this is the equation of a parabola. If, by standard form you mean in vertex form, then:
f(x)=-3(x2-6x+9)=-3(x-3)2, where the vertex is at (3,0) and the vertex is a maximum turning-point, so the parabola is like an inverted narrow U with gradually spreading arms.