(x-tanx)/(x-sinx)=(x-sinx/cosx)/(x-sinx)=(xcosx-sinx)/((x-sinx)cosx)最简单的是采用级数展开的方法来做sinx=x-x³/6+o(x³)cosx=1-x²/2+o(x²)则xcosx-sinx=x-x³/2-x+x³/6+o(x³...