Understanding (Square root of X) on Graph

I understand how these look on the graph.

(The /, U, C are just an example of what they look like on the graph)

Y = X looks like /

Y = X^2 looks like U

X = Y looks like /

X = Y^2 looks like C

However I don't understand why the (square root of X) looks the way it does on the graph.

http://img24.imageshack.us/img24/4939/xgraph.jpg

I also know that Negative (Square root of X) is flipped on the Y axis.

Even though I know this, I don't understand why it ends up like this.

Can anyone explain to me.