[tex]The vertex form:\ y=a(x-p)^2+q\ where\ (p;\ q)-coordinates\ of\ the\ vertex[/tex]
The range of function [tex]y=ax^2+bx+c[/tex]
if a > 0 then the range R = [q; ∞)
if a < 0 then the range R = (-∞; q]
We have: [tex]y=-3(x-1)^2-4\\\\a=-3 < 0\ and\ q=-4[/tex]
therefore the range [tex]R=(-\infty;-4][/tex]
