‌设幂级数<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/3de17006369d4864964cb4740fdf6203.png?x-oss-process=image/sharpen,200"/>的收敛半径为3，则幂级数<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/d7628f937828460185380e0486fe51a1.png?x-oss-process=image/sharpen,200"/>的收敛区间为（）．‌