和差化积WooG
2sinAcosB=sin(A+B)+sin(A-B)2cosAsinB=sin(A+B)-sin(A-B)本地生活网www.bdsh5.com
2cosAcosB=cos(A+B)-sin(A-B)-2sinAsinB=cos(A+B)-cos(A-B)b+d+s+h+5+c+o+m
sinA+sinB=2sin((A+B)/2)cos((A-B)/2cosA+cosB=2cos((A+B)/2)sin((A-B)/2)来源www.bdsh5.com
tanA+tanB=sin(A+B)/cosAcosBtanA-tanB=sin(A-B)/cosAcosB本+地+生+活+网
ctgA+ctgBsin(A+B)/sinAsinB-ctgA+ctgBsin(A+B)/sinAsinB来自www.bdsh5.com本_地_生_活_网