R - Compute Cross Product of Vectors (Physics)

Question

What am I doing wrong?

> crossprod(1:3,4:6)
     [,1]
[1,]   32

According to this website:http://onlinemschool.com/math/assistance/vecto

Answer 1

crossprod does the following: t(1:3) %*% 4:6

Therefore it is a 1x3 vector times a 3x1 vector --> a scalar