fn1xfn的精选

问题详情：设f0(x)=sinx,f1(x)=f0′(x),f2(x)=f1′(x),…,fn+1(x)=fn′(x),n∈N,则f2015(x)=()          B.-sinx          D.-cosx【回答】D.由题意,f1=cosx,f2=-sinx,f3=-cosx,f4=sinx,…,f2015(...