y = -2/3*x^2+3*x+5/3 (green) y = floor(x) (red) y = 211/30+341/360*x-3/2*x^2-71/288*x^3+37/240*x^4-19/1440*x^5 (blue) -3 ≤ x ≤ 7, -4 ≤ y ≤ 8