some maths problems

if you could tell me how you worked it out jut quickly that would be awesome:

1/ 4^-2

EDIT : it's 1/16 i got it now :P
hel with other 2 pl0x?

2/ (2root2)^2

3/ (1^3 + 2^3 + 3^3) ^1/2

btw ^ means to the power of and thanks in advance you wikl be repped + thanked for help

thanks for replying,
although sorryi meant like that's question 3, not divide taht by 3.

ALthough it gave me the answer as 6 so thanks :P