Math Help - Reparametrization and vector fields

1. Reparametrization and vector fields

Let $Y$ be a vector field on a curve $\alpha$. If $\alpha (h)$ is a reparametrization of $\alpha$, show that the reparametrization $Y(h)$ is a vector field on $\alpha (h)$.

I'm a bit stuck and would appreciate some help.

2. Originally Posted by Zennie
Let $Y$ be a vector field on a curve $\alpha$. If $\alpha (h)$ is a reparametrization of $\alpha$, show that the reparametrization $Y(h)$ is a vector field on $\alpha (h)$.
I don't know which is the problem. If $h$ is a reparametrization of $\alpha$ then, there exists $Y\circ \alpha \circ h$ .