[alogo] An Algebraic Locus

Consider a circle c and an angle <(HIJ). Take a point M on the circle c and build the angle <(MKN) equal to <(HIJ). Consider a point O on MN such that the ratio OM/ON = m remains constant.
Construct P by the recipe KP = (KM)*(KN)*(KO) (as complex numbers). Then take Q on OP such that QP/QO = n remains constant.

The locus of Q as M moves on the circle c is curve k.

Switch to the "Select on contour" tool (Ctrl+2) and pick-move point O (changing the ratio m). The ratio OK/OP remains fixed, the curve k transforms to a similar one.
Pick-move point Q on OP (changing the ratio n). The curve k changes its shape. However the curve (modulo similarity) does not depend on the measure of angle <(JIH). Though it depends on the radius of the circle c.

[0_0] [0_1] [0_2]
[1_0] [1_1] [1_2]



Produced with EucliDraw©