设曲线y=f(x)在原点与曲线y=sinx相切,求lim(n趋无穷)根号n*根号（f(2/n)）

lim(n->∝)√n*√f(2/n)=lim(n->∝)√2 *√[f(2/n)/(2/n)]=√2lim(n->∝)√f(2/n)/(2/n)n->∝,2/n->0,u=2/n=√2lim(u->0)√[f(u)/u]f'(u)|u=0 =lim(u->0)f(u)/uy=sinx,y'=cosxf'(x)|x=0=cos0=1,lim(u->0)f(u)/u=1lim...