若SinaCosb+CosaCocb=0.求SinaCosa+SinbCosb=?
热心网友
SinaSinb+CosaCocb=Cos(a-b)=0a-b=90+180kk为奇数时SinaCosa+SinbCosb=sin(b+90+180k)cosa+sinbcos(a-90-180k)=-cosbcosa-sinbsina=0k为偶数时SinaCosa+SinbCosb=sin(b+90+180k)cosa+sinbcos(a-90-180k)=cosbcosa+sinbsina=0综上所述，SinaCosa+SinbCosb=0