下列函数中，在<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/71e426ec0e214cd4baddf957e26b74c2.png?x-oss-process=image/sharpen,200"/>时与<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/b2cf6bc3d359467f8ef41b774a5c43dc.png?x-oss-process=image/sharpen,200"/>不等价的无穷小量是（）.