Find the dot product of $\mathbf { u }$ and $\mathbf { v }$.
$$\mathbf { u } = 9 \mathbf { i } - 5 \mathbf { j } - 9 \mathbf { k } , \mathbf { v } = - 2 \mathbf { i } + 6 \mathbf { j } + 5 \mathbf { k }$$
A) $- 93$
B) 4
C) $- 18 \mathbf { i } - 30 \mathbf { j } - 45 \mathbf { k }$
D) $- 3$
E) $7 \mathbf { i } + \mathbf { j } - 4 \mathbf { k }$

Question

Quizplus · Accepted Answer

The dot product of two vectors $\mathbf{u} = a\mathbf{i} + b\mathbf{j} + c\mathbf{k}$ and $\mathbf{v} = d\mathbf{i} + e\mathbf{j} + f\mathbf{k}$ is calculated as $ad + be + cf$. For $\mathbf{u} = 9\mathbf{i} - 5\mathbf{j} - 9\mathbf{k}$ and $\mathbf{v} = -2\mathbf{i} + 6\mathbf{j} + 5\mathbf{k}$, the dot product is $9(-2) + (-5)(6) + (-9)(5) = -18 - 30 - 45 = -93$.

Find the Dot Product Of u\mathbf { u }u And v\mathbf { v }v

Find the Dot Product Of $\mathbf { u }$ And $\mathbf { v }$