常用三角公式 ()expG8)-cos8+jsin日 (2)cosxx 方epG0)-ep附0y (3)sm0= (④)sin26+cos201 (5)cos0-sin20=cos (20) (6cos20-号+cs(20)1 (⑦)sim20-21-cs(20)] (8)2sine cose =sin (20) (9)Sin(a±B)=sina cosB±cosa sin B (10)cos(a±B)=-sina cosB cosa sin B ammasmB-oa-Bew-a+g 2eosacsB-eosa-B)Hcoga+Bn (13)sin cossin(a)+sin(+常用三角公式 (1) exp(jθ )=cosθ +jsinθ (2) cosθ = 2 1 [ exp(jθ )+ exp(-jθ )] (3) sinθ = 2 j 1 [ exp(jθ )－exp(-jθ )] (4) sin2 θ +cos2 θ =1 (5) cos 2 θ －sin2 θ = cos（2θ ） (6) cos 2 θ = 2 1 [1+ cos（2θ ）] (7) sin2 θ = 2 1 [1－cos（2θ ）] (8) 2 sinθ cosθ =sin（2θ ） (9) Sin（α ± β ）=sinα cos β ± cosα sin β (10)cos （α ± β ）=sinα cos β ∓ cosα sin β (11)sinα sin β = 2 1 [cos(α − β )cos－(α + β )] (12)cosα cos β = 2 1 [cos(α − β )+cos(α + β )] (13)sinα cos β = 2 1 [sin(α − β )+sin(α + β )]