3. Find the greatest and least values of the function $y=e^{2 x^{2}-4 x-6}$ on the interval $[0 ; 3]$.
Solution: $y=e^{2 x^{2}-4 x-6}$ on $[0 ; 3] . y^{\prime}=e^{2 x^{2}-4 x-6}(4 x-4)=0, x=1$, $y(0)=e^{6}, y(1)=e^{-4}, y(3)=e^{12}$.