Questions: Find a · b. a=7i+j, b=i-2j+k Find a · b. a=5,b=6, the angle between a and b is 30°. If u is a unit vector, find u · v and u · w. (Assume v and w are also unit vectors.) u · v=

Transcript text: Find $\mathbf{a} \cdot \mathbf{b}$. \[ \mathbf{a}=7 \mathbf{i}+\mathbf{j}, \quad \mathbf{b}=\mathbf{i}-2 \mathbf{j}+\mathbf{k} \] Find $\mathbf{a} \cdot \mathbf{b}$. $|\mathbf{a}|=5,|\mathbf{b}|=6$, the angle between $\mathbf{a}$ and $\mathbf{b}$ is $30^{\circ}$. If $\mathbf{u}$ is a unit vector, find $\mathbf{u} \cdot \mathbf{v}$ and $\mathbf{u} \cdot \mathbf{w}$. (Assume $\mathbf{v}$ and $\mathbf{w}$ are also unit vectors.) \[ \mathbf{u} \cdot \mathbf{v}= \]