\[1)\ y = \log_{2}\left( x^{3} + 4 \right);\]
\[y^{'}(x) = \frac{3x^{2}}{\left( x^{3} + 4 \right) \bullet \ln 2}.\]
\[2)\ y = 2^{x^{2} + 3x};\]
\[y^{'}(x) = (2x + 3) \bullet 2^{x^{2} + 3x} \bullet \ln 2.\]
\[3)\ y = tg^{2}\ 2x;\]
\[y^{'}(x) = 2 \bullet 2\ tg\ 2x \bullet \frac{1}{\cos^{2}{2x}} =\]
\[= \frac{4\sin{2x}}{\cos^{3}{2x}}.\]
\[4)\ y = \ln\frac{x - 2}{x + 2};\]
\[y^{'}(x) = \frac{(x + 2) - (x - 2)}{(x + 2)^{2}} \bullet \frac{x + 2}{x - 2} =\]
\[= \frac{4}{(x + 2)(x - 2)} = \frac{4}{x^{2} - 4}.\]