(2). Let $$T: V \to W$$ be a linear transformation. Please show that $$T$$ is one to one if and only if

$$\text{Ker}(T) = \{\vec{0}_V\}$$. (10% 證明中零向量請用足標表明所在之空間，如 $$\vec{0}_V$$ 表示 $$V$$ 的零向量)