设g(x)=f(x)e^(dx),由题意得g(x)在(a,b)上可导,[a,b]内连续,又g(a)=f(a)e^(da)=0g(b)=f(b)e^(da)=0即g(a)=g(b)对g(x)在[a,b]区间应用罗尔定理,至少存在一点c,使得g'(c)=0即f'(c)e^(dc)+df(c)e^(dc)=0对上式左右除以e...