Thread: Direct Sum & Linear Mappings

Originally Posted by manygrams

Hi there,

I was just wondering if anyone could tell me if my answer was somewhat right.

An example in my textbook asks:

If T:V X V V is the linear mapping T(x,y)=x-y, determine the kernel and range of T.

My Answer:
Let a=(x,y)
Ker T = {a V X V | Ta=0}

0 =Ta
=T(x,y)
= x-y
y = x

Therefore, Ker T = {(x,y) V X V | x=y}

Im T = T(V X V) = {Ta | a V}
= T(x,y)
= x - y

Make sense?

The first part does make much sense, the second one much less: the image is the whole of V (why?)

Tonio