if two linearly independent vectors are mapped to a same non zero vector by a linear transformation then it's nullspace is non trivial? [closed]

Solution 1:

$T\in {\scr{L}}{(V, W) }$

$v_1, v_2 \in V$ Linearly independent. (Here, $v_1 \neq v_2 $ is sufficient to prove the claim)

$T(v_1) =T(v_2) $

$T(v_1 -v_2) =0$

$v_1-v_2 \in Null(T) $

And ,$v_1 -v_2\neq 0$

$T$ is not injective linear map.