Thread: generate

Let T: V-> W be a linear map, and let x1,....,xm and y1,...yn be two lists of vector in V. Suppose that

(a) x1,...xm generate Ker T and
(b) T(y1),...,T(yn) genterate W.

Show that the list x1,....,xm, y1,...,yn generates V.

Pls help

Originally Posted by mathbeginner

Pls help

I helped you with the other one, what have you done for this one?

I know I can use b and show the T is subjective.
then since T is subjective and T(y1),...(T(yn) generates W then y1,...,yn generates V.
but I don't know how to show T is subjective.

and I don't know how to start a yet.

Originally Posted by mathbeginner

I know I can use b and show the T is subjective.
then since T is subjective and T(y1),...(T(yn) generates W then y1,...,yn generates V.
but I don't know how to show T is subjective.

and I don't know how to start a yet.

Firstly, it's [i]surjective[/b], secondly you think that ?

Originally Posted by Drexel28

Firstly, it's [i]surjective[/b], secondly you think that ?

but how can I show that T is surjective?

I'm working on this question as well. I thought the same but realized that it only proves some vectors in W can be generated by T(b_1*y_1 + ... + b_n*y_n). this is correct, right?

Do you have any hints? I'm pretty stuck but I've been working on it for a while.

EDIT> I was thinking of using dimV=dimT(v)+dim(KerT) (v in V), would this help at all?