x趋向于零,sin2x^3与4x(1-cosx)是等价无穷小?(sinx)^2与6xsinx是同价无穷小?

问题描述:

x趋向于零,sin2x^3与4x(1-cosx)是等价无穷小?(sinx)^2与6xsinx是同价无穷小?

sin2x^3~2x^3
4x(1-cosx)~4x*1/2*x^2=2x^3
故sin2x^3与4x(1-cosx)是等价无穷小
(sinx)^2~x^2
6xsinx~6x^2
(sinx)^2与6xsinx是同价无穷小