\[1)\ y = \sin x \bullet \cos x = \frac{1}{2}\sin{2x}\]
\[- 1 \leq \sin{2x} \leq 1\]
\[- \frac{1}{2} \leq \frac{1}{2}\sin{2x} \leq \frac{1}{2}.\]
\[Ответ:\ \ E(y) = \left\lbrack - \frac{1}{2};\ \frac{1}{2} \right\rbrack.\]
\[2)\ y = \log_{2}\left( x^{2} + 2 \right);\]
\[y^{'}(x) = \frac{2x}{\left( x^{2} + 2 \right) \bullet \ln 2} \geq 0;\]
\[2x \geq 0\]
\[x \geq 0;\]
\[y(0) = \log_{2}2 = 1.\]
\[Ответ:\ \ E(y) = \lbrack 1;\ + \infty).\]