How do you compute the dot product for u=3i+2j and v=-2i-3j?

Sep 22, 2016

$- 12$

Explanation:

We have: $u = 3 i + 2 j$ and $v = - 2 i - 3 j$

$\implies u \cdot v = \left(3 i + 2 j\right) \cdot \left(- 2 i - 3 j\right)$

$\implies u \cdot v = \left(3 \cdot \left(- 2\right)\right) + \left(2 \cdot \left(- 3\right)\right)$

$\implies u \cdot v = - 6 - 6$

$\implies u \cdot v = - 12$