# Math Help - Linear Algebra help

1. ## Linear Algebra help

Let V, W, and Z be vectors spaces, and let T: V --> W and U: W --> Z be linear.

Prove that if UT is 1-1, then T is 1-1.

b) does U have to be 1-1?

2. Part (a) is straightforward (use the definition of 1–1 function).

Part (b): No, $U$ only has to be 1–1 on the subspace $T(W)$.