摘要
本文目的是研究两卵形弧间的等距对应,所得的主要结果是下列两定理:定理设C和C ̄*是两条正则的卵形线,它们的长度相等,C→C ̄*是等距映射,则在C上有4个不同的点A1、A2、A3、A4使C在A_i的曲率等于C*在=1,2,3,4.)。定理设C和C ̄*都是以A、B为端点的卵形弧,它们的长度相等;C→C ̄*是等距映射使;M为C上一点;对于AM上任P有对MB上任一点心P有.则α*≤α,β≥β*其中α(α*)是C(C ̄*)在A的弦切角,β(β ̄*)是C(C ̄*)在B的弦切角。
In this paper,we study the isometric correspondence between two oval arcs. The main results are the following theorems:Theorem Let C and C* be two regular ovals with the same legth,an isometric correspondence between C and C*. Then there are 4 points A1,A2,A3,A4 on C such that the curvature of C at A1 is equal to the curvature of C* at (i=1,2,3,4.).Theorem Let C and C* be two oval arcs with the same length and the same end points A, B;M a point on C; an isometric mapping such that (P)) for each point on AM and k(P)≤k((P)) for each point on MB.Then α≤α,β*≥β, where α(α*) is the angle between the tangent to C(C*) at A and AB,β(β*) is the angle between the tangent to C(C*)at B and BA.