$$\eqalign{
& 1)\,\,y = 3{\left( {3\sin x + 4\cos x} \right)^2} + 4\left( {3\sin x + 4\cos x} \right) + 1 \cr
& Dat\,\,t = 3\sin x + 4\cos x \Rightarrow t \in \left[ { - 5;5} \right] \cr
& y = 3{t^2} + 4t + 1\,\,\,voi\,\,t \in \left[ { - 5;5} \right] \cr} $$
=> GTNN = -1/3, GTLN = 96.