Chapter 11 - Vectors and Vector-Valued Functions - 11.4 Cross Products - 11.4 Exercises - Page 797: 2

$\theta = arcsin(\frac{|\textbf{u} \times \textbf{v}|}{|\textbf{u}||\textbf{v}|})$

Theorem 11.3 : $|\textbf{u} \times \textbf{v}| = |\textbf{u}||\textbf{v}|sin(\theta)$ Solve for $sin(\theta)$ : $sin(\theta) = \frac{|\textbf{u} \times \textbf{v}|}{|\textbf{u}||\textbf{v}|}$ Solve for $\theta$ : $\theta = arcsin(\frac{|\textbf{u} \times \textbf{v}|}{|\textbf{u}||\textbf{v}|})$