# Dot and cross product

Pippa
Explain, for example, why you can cross three vectors (two at a time, following the usual rules), but not dot three vectors. Do you see the dot product "in action" in matrix multiplication? What sort of insights can the dot product give when trying to comprehend matrix multiplication?

jaqueh
the dot product is a scalar, the cross product is still a vector

The dot product coincides with matrix multiplication , when your matrices are 1xn and
nx1.

Pippa
Thanks Guys :D

jaqueh
np-
basically you get a number if its 1xn and nx1 and another vector if its nx1 and nx1

brinethery
Yep, a scalar dotted with a vector is undefined. Finally, something I can answer! :-)