已知cos(派/4-a法)=1/7,sin(3派/4+贝塔)=11/14,派/4

已知cos(派/4-a法)=1/7,sin(3派/4+贝塔)=11/14,派/4
已知cos(派/4-a法)=1/7,sin(3派/4+贝塔)=11/14,派/4

已知cos(派/4-a法)=1/7,sin(3派/4+贝塔)=11/14,派/4
sin(a+贝塔)=-cos[π/2+(a+贝塔)]=-cos[(3派/4+贝塔)-(派/4-a法)]=-sin(3派/4+贝塔)sin(派/4-a法)-cos(3派/4+贝塔)cos(派/4-a法),再根据条件推出,sin(派/4-a法)=4√3/7,cos(3派/4+贝塔)=-5√3/14,代入即可求得结果.