x(t)和h(t)分别如图所示，则<img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/e20c538ee5e44fd3870e28f941783be4.png?x-oss-process=image/sharpen,200"/>等于（）。<br/> <img src="http://jgxm-question.oss-cn-beijing.aliyuncs.com/psst/files/4856434da5e84fed84d0cad467e8b94d.jpeg?x-oss-process=image/sharpen,200"/>