Convexity limit angles for isoptics
Convexity limit angles for isoptics
Abstract Given an oval C in the plane, the $$\alpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> -isoptic $$C_\alpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msub> <mml:mi>C</mml:mi> <mml:mi>α</mml:mi> </mml:msub> </mml:math> of C is the plane curve composed of the points from which C can be seen under the angle $$\pi -\alpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> …