wxMaxima - initial calculations, first use - finding an angle by the inverse cosine

So I am beginning my endeavor into wxMaxima which I am using for a Mathematica replacement. So far not so bad, I will just have to get use to the syntax and the ways things are done in Maxima. Thus, I will be posting to my blog regularly once I have accomplished, done an example, or figured something out in Maxima even if it is as small and minute as calculation the sine or arcosine whuch is exactly what my first task has been to do.

I am taking a vector calculus course this semester and I needed to find the angle between two vectors. The formula for this is

\begin{equation} \textbf{u} \cdot \textbf{v} = |\textbf{u}||\textbf{v}| \cos \theta \end{equation}