Given u = 3i − 8j and v = −4i + 8j, what is u • v?

73
8
−76
−56

Question

Given u = 3i − 8j and v = −4i + 8j, what is u • v?

73
 8
 −76
 −56

Extrinix · Answer

$(3i-8j)(-4i+8j)$

That’s what “$u \times v$ is, just solve it now

pacman25 · Answer

@extrinix Could you help solve it

pacman25 · Answer

ik how to get the equation thats the easy part haha

Extrinix · Answer

Okay well, the easiest way is to stack them on top of each other, like so

$~~3i-8j \
\times -4i+8j$

Extrinix · Answer

And in doing this, you’ll see that it will be close to this:

$Xi^2 \underline{+} Xj^2$
($X$ is a number; when solved, just replace it with the number)

I’ll let you do the math

pacman25 · Answer

lmao thanks bro

pacman25 · Answer

@extrinix Ngl man i completely forgot ALL of this can you finish da problem for me sorry