[Math] Why is the dimension of a kernel with the basis {[0,0,0]} equal to zero

discrete mathematicslinear algebravector-spaces

What is the dimension of a kernel with the basis {[0,0,0]}?

I'm confused because the definition of the dimension is number of vectors in a basis. So there is 1 vector here which is [0,0,0].

Why does my professor say that the dimension of kernel is zero? He mentioned something about the zero vector space.

Best Answer

The space spanned by $[0,0,0]$ is $\{[0,0,0]\}$, i.e. then null space.

A basis needs to be made of linearly independant vectors, and thus a family which contains the null vector cannot be a basis !

The basis of the null space would just be the empty set $\emptyset$, hence its dimension is $0$