Halliday, Resnick & Walker — Vectors: Problem 35

Two vectors, \(\vec{r}\) and \(\vec{s}\), lie in the \(xy\) plane. Their magnitudes are 4.50 and 7.30 units, respectively, and their directions are 320° and 85.0°, respectively, as measured counterclockwise from the positive \(x\) axis. What are the values of (a) \(\vec{r} \cdot \vec{s}\) and (b) \(\vec{r} \times \vec{s}\)?