必修五解三角形复习课件

第一章第一章解三角形解三角形2021/6/3012021/6/3022021/6/3032021/6/3042021/6/3052021/6/3062021/6/3072021/6/3082021/6/3092021/6/30102021/6/30112021/6/30122021/6/3013在在ABC中，角中，角A，B，C的对边分别为的对边分别为a，b，c，且满，且满足足(2ab)cos Cccos B，ABC的面积的面积S10，c7.(1)求角求角C；(2)求求a，b的值的值解解(1)(2ab) cos Cc cos B，(2sin Asin B) cos Csin C cos B，2sin A cos Csin B cos Ccos B sin C，即即2sin A cos Csin (BC)，2sin A cos Csin A.【例例2】2021/6/30142021/6/30152021/6/30162021/6/30172021/6/30182021/6/30192021/6/30202021/6/30212021/6/30222021/6/30232021/6/30242021/6/30252021/6/30262021/6/3027 若有不当之处，请指正，谢谢！若有不当之处，请指正，谢谢！