Find a⋅b if |a|=12, |b|=9, and the angle between a and b is π/2.

Answer 1

Hi Josemar,

There is a very important formula governing the dot product. It is the following:

a*b = |a||b|cos(theta)

where * represents the dot product, a and b are vectors of the same dimensions, and theta is the (smallest) angle between the vectors.

Does that help?