Question

Use the vectors u = 4, 4 and v = −8, 3 to find the indicated quantity. (u · v)v

Answer 1

The scalar product, or dot product, of two vectors is the sum of the products of corresponding coordinates.

... u·v = (4, 4)·(-8, 3) = 4(-8) + 4(3) = -20

Then the product of a scalar and a vector is a vector with each of the original coordinates multiplied by the scalar.

... (u·v)v = -20v = -20(-8, 3) = (160, -60)