Difference between kernel of a matrix and kernel of a transformation?

652 Views Asked by At

Does the word "kernel" carry different meanings in the contexts of matrices and transformations? Or are the definitions of the two in those two contexts intertwined in some way?

I know the kernel of a matrix to be it's null space. I haven't been taught about the kernel of a transformation yet, but I looked it up and it's a bunch of complicated stuff that doesn't make much sense (it's apparently every vector v that results in a transformation T outputting the zero vector?)

Are they just two different ideas?

2

There are 2 best solutions below

0
On

The kernel of a matrix $A$ is the space of those vectors $v$ such that $A.v=0$. The kernel of a linear transformation $T$ is the space of those vectors $v$ such that $T(v)=0$. So, it is basically the same thing.

0
On

Every linear transformation from one finite dimensional space to another can be written as a matrix. The only difference between "kernel of a linear transformation" and "kernel of a matrix" would be in the case of a linear transformation over infinite dimensional spaces which cannot be written as a matrix. An example would be the "differentiation" operator on the space of all differentiable functions. The kernel of that operator is the subspace of all constant functions.