fn1xfn的精選

問題詳情：設f0(x)=sinx,f1(x)=f0′(x),f2(x)=f1′(x),…,fn+1(x)=fn′(x),n∈N,則f2015(x)=()          B.-sinx          D.-cosx【回答】D.由題意,f1=cosx,f2=-sinx,f3=-cosx,f4=sinx,…,f2015(...