[tex]\sqrt[\big4]{4^{\big{12}}} = \\ \\ = \sqrt[\big4]{4^{\big{4\cdot 3}}} = \\ \\ = \sqrt[\big4]{4^{\big{4}}\cdot 4^{\big{3}}} =\\ \\ = \sqrt[\big4]{4^{\big{4}}}\cdot \sqrt[\big4]{4^{\big{3}}} =\\ \\ = 4\cdot\sqrt[\big4]{4^{\big3}} =\\ \\ = 4\sqrt[\big4]{64}[/tex]
