Find a· b.
-$$a = \langle 5 , - 8 \rangle , \quad b = \langle 3,1 \rangle$$
A) $\langle 8 , - 7 \rangle$
B) 7
C) 23
D) $\langle 15 , - 8 \rangle$

Question

Quizplus · Accepted Answer

The dot product of two vectors $a = \langle a_1, a_2 \rangle$ and $b = \langle b_1, b_2 \rangle$ is calculated as $a \cdot b = a_1b_1 + a_2b_2$. For $a = \langle 5 , - 8 \rangle$ and $b = \langle 3,1 \rangle$, the dot product is $5*3 + (-8)*1 = 15 - 8 = 7$.

Find A· B - a=⟨5,−8⟩,b=⟨3,1⟩a = \langle 5 , - 8 \rangle , \quad b = \langle 3,1 \ranglea=⟨5,−8⟩,b=⟨3,1⟩

Find A· B
- $a = \langle 5 , - 8 \rangle , \quad b = \langle 3,1 \rangle$