设<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/4fd98592605f49b59b04a505f0a60272.png?x-oss-process=image/sharpen,200"/>是由方程<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/d81139f3b79a4260adf6b388ab997d56.png?x-oss-process=image/sharpen,200"/>确定的隐函数，则<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/92259ee81f4f4c37a6f6226afa270168.png?x-oss-process=image/sharpen,200"/>等于( ).