lim(x趋近于0)(sinx/x)的(1/1-cosx)次方 = lim(x趋近于0)(1+sinx/x -1)的(1/1-cosx)次方 =e的{ lim(x趋近于0)(sinx/x-1)×【1/(1-cosx)】次方} 下解 lim(x趋近于0)(sinx/x-1)×【1/(1-cosx)】 = lim(x趋近于0)(sinx-x)/x(1-cosx)】 = lim(x趋近于0)(sinx-x)/(x*x2/2) (等价代换) =2 lim(x趋近于0)(sinx-x)/x3 =2 lim(x趋近于0)(cosx-1)/3x2 =2 lim(x趋近于0)(-x2/2)/3x2 =-1/3 所以原式=e的(-1/3)次方.可这样表示:e^(-1/3)