设函数<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/9257abf33a044915a24757c369da9448.png?x-oss-process=image/sharpen,200"/>在闭区间<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/28cd67c989e34df982eaf42e885f7f00.png?x-oss-process=image/sharpen,200"/>上有定义，在开区间<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/fb4cd163e8d947c782a0ce39c0171144.png?x-oss-process=image/sharpen,200"/>内可导，则（）