張幼賢莊曜豪2019-09-052014-07-012019-09-052013http://etds.lib.ntnu.edu.tw/cgi-bin/gs32/gsweb.cgi?o=dstdcdr&s=id=%22GN0698400044%22.&%22.id.&http://rportal.lib.ntnu.edu.tw:80/handle/20.500.12235/101808In this thesis, we use a pair of coupled upper and lower solution to the SIR(susceptible,infective and removed) model. We show that there exist two equilibrium, one is diseasefree equilibrium and another one is stationary positive equilibrium, which means that the disease becomes stable.SIR modelupper and lower solutions