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[1NV] Let \(Iโ โ\) be an interval.
A continuous function \(๐พ:Iโ X\) is called parametric curve, or more simply in the following curve.
If \(๐พ\) is a homeomorphism onto its image, the curve is said to be embedded.
If \(X=โ^ n\) and \(๐พ\) is of class \(C^ 1\) and \(๐พ'(t)โ 0\) for every \(tโ I\), then \(๐พ\) is called an immersed curve or regular curve.
We will call support or trace the image \(๐พ(I)\) of a curve.
The term arc is also used as a synonym for curve; 1 this term is mainly used when the curve is not (necessarily) closed.