Question

Determine whether the expression make sense mathematically, if not explain why.

a) ||u|| . ||v|| b) (u . v) - w c) (u . v)-k d) k . u

the . are dot product. I feel like a and c isn't possible but don't quite know the reason

Answer 1

a) doesn't make sense because you can't dot product two scalars
b) doesn't make sense because you can't combine a vector and a scalar by addition
c) doesn't make sense for same reason as b (unless k is a constant)
d) makes sense (even if k is a constant)

Answer 2

oh w is a vector

Answer 3

but can we dot product two vectors then subtract them with another vector?

Answer 4

But the dot product of two vectors is a scalar.

Answer 5

Oh make sense thank you everyone