证明sina+sinb-sinasinb+cosacosb=1

来源:学生作业帮助网 编辑:作业帮 时间:2024/04/29 02:53:15
证明sina+sinb-sinasinb+cosacosb=1

证明sina+sinb-sinasinb+cosacosb=1
证明sina+sinb-sinasinb+cosacosb=1

证明sina+sinb-sinasinb+cosacosb=1
证明:∵sina+sinb-sinasinb+cosacosb =sina+sinb·(1-sina)+cosa·cosb =sina+sinb·cosa+cosa·cosb =sina+cosa·(sinb+cosb) =sina+cosa =1 ∴sina+sinb-sinasinb+cosacosb=1

sina+sinb-sinasinb+cosacosb =sina(1-sinb)+sinb+cosacosb =sinacosb+cosacosb+sinb =cosb(sina+cosa)+sinb =cosb+sinb =1 希望我的答案可以帮助到你!