reciprocal function

Between degree of operating leverage DOL and degree of margin of safety MRS are reciprocal ( 3) DOL is a monotone minus function to sale income.

经营杠杆度DOL与安全边际系数MRS互为倒数关系，两者都对企业的经营状况起警示作用；③经营杠杆度DOL对销售收入S的函数为单调减函数；

Before 1980, China had already had social security, family insurance and reciprocal insurance which have not only the function of economic indemnification, but also the functions of services, spiritual comfort, feeling support.

在中国恢复重建商业保险之前，中国就有社会保障制度、家庭保险制度、互助保险制度存在。这些制度不仅具有商业保险的经济保障功能，还有服务保障、精神慰藉、情感支持等功能。