精选优质文档-倾情为你奉上三角函数公式1、两角和公式 sin(A+B) = sinAcosB+cosAsinB sin(A-B) = sinAcosB-cosAsinB cos(A+B) = cosAcosB-sinAsinB cos(A-B) = cosAcosB+sinAsinB tan(A+B) = (tanA+tanB)/(1-tanAtanB) tan(A-B) = (tanA-tanB)/(1+tanAtanB) cot(A+B) = (cotAcotB-1)/(cotB+cotA) cot(A-B) = (cotAcotB+1)/(cotB-cotA) 2、倍角公式 tan2A = 2tanA/(1-tan2 A) Sin2A=2SinA?CosA Cos2A = Cos2 A-Sin2 A =2Cos2 A1 =12sin2 A 3、三倍角公式 sin3A = 3sinA-4(sinA)3; cos3A = 4(cosA)3 -3cosA tan3a = tan
