1) $$√{3136} = √{2^6 \cdot 7^2} = 2^3 \cdot 7 = 8 \cdot 7 = 56$$.
2) $$√{6084} = √{2^2 \cdot 3^2 \cdot 13^2} = 2 \cdot 3 \cdot 13 = 78$$.
3) $$√{√{4356}} = √{√{2^2 \cdot 3 \cdot 11^2}} = √{2 \cdot 3 \cdot 11} = √{66}$$.
4) $$√{1764} = √{2^2 \cdot 3^2 \cdot 7^2} = 2 \cdot 3 \cdot 7 = 42$$.
Ответ: 1) 56; 2) 78; 3) $$√{66}$$; 4) 42.