特殊模型抽象函數(shù)
正比例函數(shù)f(x+y)=f(x)+f(y)
冪函數(shù)f(xy)=f(x)f(y)或f(x/y)=f(x)/f(y)
指數(shù)函數(shù)f(x+y)=f(x)f(y)或f(x-y)=f(x)/f(y)
對數(shù)函數(shù)f(xy)=f(x)+f(y)f(xy)=f(x)-f(y)
余弦函數(shù)f(x)+f(y)=2f(x+y/2)f(x-y/2)
正切函數(shù)f(x+y)=f(x)+f(y)/1-f(xy)