Find the dot product of u and v. $$\begin{array} { l }
\mathbf { u } = \langle - 7,1 \rangle \
\mathbf { v } = \langle 4 , - 5 \rangle
\end{array}$$
A)-31
B)-29
C)-33
D)-37
E)-35

Question

Find the dot product of u and v.​ $$\begin{array} { l } 
\mathbf { u } = \langle - 7,1 \rangle \
\mathbf { v } = \langle 4 , - 5 \rangle
\end{array}$$ ​
A)-31
B)-29
C)-33
D)-37
E)-35

Quizplus · Accepted Answer

To find the dot product, we multiply the corresponding components of u and v and then add them up.

u = (1, -2, 3, -4)
v = (5, -6, 7, -8)

u · v = (1)(5) + (-2)(-6) + (3)(7) + (-4)(-8) 
u · v = 5 + 12 + 21 + 32
u · v = 70 
Therefore, the dot product of u and v is 70, which corresponds to choice C.

Find the Dot Product of U and V u=⟨−7,1⟩v=⟨4,−5⟩\begin{array} { l } \mathbf { u } = \langle - 7,1 \rangle \\\mathbf { v } = \langle 4 , - 5 \rangle\end{array}u=⟨−7,1⟩v=⟨4,−5⟩​

Find the Dot Product of U and V $\begin{array} { l } \mathbf { u } = \langle - 7,1 \rangle \\\mathbf { v } = \langle 4 , - 5 \rangle\end{array}$