Question

given the vectors u and v such that abs (u) = 3 and abs (v) = 5, determine the scalar product of (u-v)

Answer 1

the scalar product of what?

Answer 2

Sorry this is the question taken from a book here in Brazil. The answer is -16.

Answer 3

the question must be asking what is the scalar product (otherwise known as the dot product) of
\[ (u-v)\cdot(u+v)\]

Answer 4

Thanks your formulae is right.