求解lim(x趋近0)[(1-cosx) sin2x]/(x^3)的极限.

问题描述:

求解lim(x趋近0)[(1-cosx) sin2x]/(x^3)的极限.

等价无穷小方法
1-cosx—x^2/2
sin2x-2x
lim(x趋近0)[(1-cosx) sin2x]/(x^3)=x^2/2*2x/x^3=1