We take the functional theoretic algebraC of curves. For each loop γ at 1, and each positive integern, we define a curve called n-curve. The n-curves are interesting in two ways.
Their f-products, sums and differences give rise to many beautiful curves.
Using the n-curves, we can define a transformation of curves, called n-curving.
A curve γ in the functional theoretic algebra C, is invertible, i.e. exists if If, where, then The set G of invertible curves is a non-commutative group under multiplication. Also the set H of loops at 1 is an Abelian subgroup of G. If, then the mapping is an inner automorphism of the group G. We use these concepts to define n-curves and n-curving.
If x is a real number and denotes the greatest integer not greater thanx, then If and n is a positive integer, then define a curve by is also a loop at 1 and we call it an n-curve. Note that every curve in H is a 1-curve. Suppose Then, since.
Example 1: Product of the astroid with the ''n''-curve of the unit circle
Let us take u, the unit circle centered at the origin and α, the astroid. The n-curve of u is given by, and the astroid is The parametric equations of their product are See the figure. Since both are loops at 1, so is the product.
Example 2: Product of the unit circle and its ''n''-curve
The unit circle is and its n-curve is The parametric equations of their product are See the figure.
Example 3: ''n''-Curve of the Rhodonea minus the [Rhodonea curve]
If, then, as mentioned above, the n-curve. Therefore, the mapping is an inner automorphism of the group G. We extend this map to the whole of C, denote it by and call it n-curving with γ. It can be verified that This new curve has the same initial and end points as α.
Example 1 of ''n''-curving
Let ρ denote the Rhodonea curve, which is a loop at 1. Its parametric equations are With the loop ρ we shall n-curve the cosine curve The curve has the parametric equations See the figure. It is a curve that starts at the point and ends at. curve at N=0. Please note that the parametric equation was modified to center the curve at origin.
Example 2 of ''n''-curving
Let χ denote the Cosine Curve With another Rhodonea Curve we shall n-curve the cosine curve. The rhodonea curve can also be given as The curve has the parametric equations See the figure for.
Generalized ''n''-curving
In the FTA C of curves, instead of e we shall take an arbitrary curve, a loop at 1. This is justified since Then, for a curve γ in C, and If, the mapping given by is the n-curving. We get the formula Thus given any two loops and at 1, we get a transformation of curve This we shall call generalizedn-curving.
Example 1
Let us take and as the unit circle ``u.’’ and as the cosine curve Note that For the transformed curve for, see the figure. The transformed curve has the parametric equations
Example 2
Denote the curve called Crooked Egg by whose polar equation is Its parametric equations are Let us take and where is the unit circle. The n-curved Archimedean spiral has the parametric equations See the figures, the Crooked Egg and the transformed Spiral for.