\[\left( \frac{1}{2}\text{ab} \right)^{2} = \left( \frac{1}{2} \right)^{2} \cdot \left( \text{ab} \right)^{2} =\]
\[= \frac{1}{4}a^{2}b^{2} \Longrightarrow коэффициент\ \frac{1}{4};\ \ \]
\[степень\ 4.\]