Question

When a closed curve is parameterized by {x[t], y[t]}, then as you advance along the curve in the direction of the parameterization, which way do the tangent vectors {x'[t], y'[t]} at {x[t], y[t]} point; in the direction you are going, or in the direction opposite to the direction you are going?

Answer 1

In the direction you are going,

Step-by-step explanation:

We know that the tangent to {x[t], y[t]} are {x'[t], y'[t]}. Since {x'[t], y'[t]} are tangents at {x[t], y[t]}, we know that the tangent at a point is always parallel to the direction of the function at that point and in the direction of the function. So, the tangent vectors {x'[t], y'[t]} at {x[t], y[t]} point in my direction of motion as I move along the curve.

So, the tangent vectors {x'[t], y'[t]} at {x[t], y[t]} point in the direction you are going.