Question

How do you compute the dot product for `u=3i+4j` and `v=7i-2j`?

Answer 1

13

Explanation:

If `u=(a_1i+b_1j)=(a_1, b_1) and v = (a_2i+b_2j)=(a_2, b_2)`,

then the dot (scalar) product

`u.v=(a_1, b_1).(a_2, b_2)=a_1 b_1+a_2 b_2`.

Here, `u.v=(3, 4).(7, -2)=(3)(7)+(4)(-2)=21-8=13`.