求下列各角的正弦、余弦、正切值750° 、17π/4、-11π/6、-1020°

2个回答

  • sin750°=sin(720°+30°)=sin30°=1/2

    cos750°=cos(720°+30°)=cos30°=根号3/2

    tan750°=tan(720°+30°)=tan30°=根号3/3

    sin17π/4=sin(16π/4+π/4)=sin(π/4)=根号2/2

    cos17π/4=cos(16π/4+π/4)=cos(π/4)=根号2/2

    tan17π/4=tan(16π/4+π/4)=tan(π/4)=1

    sin(-11π/6)=sin(-12π/6+π/6)=sin(π/6)=1/2

    cos(-11π/6)=cos(-12π/6+π/6)=cos(π/6)=根号3/2

    tan(-11π/6)=tan(-12π/6+π/6)=tan(π/6)=根号3/3

    sin(-1020°)=sin(-1080°+60°)=sin60°=根号3/2

    cos(-1020°)=cos(-1080°+60°)=cos60°=1/2

    tan(-1020°)=tan(-1080°+60°)=tan60°=根号3