Ответ:

1) \(\sqrt[3]{1^6}=1\).

2) \(\sqrt[3]{3^{12}}=3^4=81\).

3) \(\sqrt[4]{\left(\frac12\right)^{12}}=\left(\frac12\right)^3=\frac18\).

4) \(\sqrt{\left(\frac13\right)^{16}}=\left(\frac13\right)^8=\frac1{6561}\).

Ответ: 1; 81; 1/8; 1/6561.