lim sin 2x / sin 5x lim arctan x / x

问题描述:

lim sin 2x / sin 5x lim arctan x / x
x趋近于0 x趋近于0

(1) sin2x 5x sin2x 2lim -------------------=lim--------------*lim------------ *------ =2/5 x→0 sin 5x x→0 sin 5x x→0 2x 5(2) arctanx (arctanx)' 1/(1+x²)lim -------------=lim ------------------...我知道了,谢谢!0/0型,求导