what does it mean to raise something to the negative one half power

I want you to look at this post.

http://web2.0calc.com/questions/indices-especially-negative-indices

You question was not covered directly so I added a new post to the end to answer your question exactly.

Note....a^-n means   1/aⁿ

So a^-1/2   means 1/a^1/2 = 1/√a

For instance....9^-1/2 = 1/9^1/2 = 1/√9 = 1/3

Does that help ??