已知sinα=<img alt="" src="http://www.weimei168.com/uploads/202208/20120921084926412641.gif" />且<img alt="" src="http://www.weimei168.com/uploads/202208/20120921084989528952.gif" />，则sin(α+<img alt="" src="http://www.weimei168.com/uploads/202208/20120921084919071907.gif" />)的值等于（）