1
sinacosb+cosasinb-sinbcosa=sinacosb
2
cosacosb+sinasinb-sinasinb=cosacosb
3
1/2*sina-sinacosπ/3+cosasinπ/3=1/2*sina-1/2*sina+√3/2*cosa=√3/2*cosa
4
√2*cosa*cosπ/4+√2*sinasinπ/4+sina=√2/1/√2*cosa+√2*1/√2sina+sina=
=cosa+sina+sina=cosa+2sina