Let $A(x) = x\sqrt{x+3}.$ Answer the following questions.

1. Find the interval(s) on which $A$ is increasing.

2. Find the interval(s) on which $A$ is decreasing.
3. Find the local maxima of $A.$ List your answers as points in the form $(a,b)$.
4. Find the local minima of $A.$ List your answers as points in the form $(a,b)$.
5. Find the interval(s) on which $A$ is concave upward.
6. Find the interval(s) on which $A$ is concave downward.