求三角函数的函数值就是sincostan15°75°105°135°165°195°225°什么的不是很常用的最好表示出带根号的形式没有这些值算题很难做

Answer 1

sin(15°)=sin(165°)=(6^0.5-2^0.5)/4 sin(75°)=sin(105°)=(6^0.5+2^0.5)/4
sin(135°)=2^-0.5 sin（195°）= -(6^0.5-2^0.5)/4 sin(225°)=-2^-0.5
cos(15°)=(6^0.5+2^0.5)/4 cos(75°)=(6^0.5-2^0.5)/4
cos(105°)=-(6^0.5-2^0.5)/4 cos(135°)=cos(225°)=-2^-0.5
cos(165°)=cos(195°)=-(6^0.5+2^0.5)/4
tan(15°)=tan(195°)=2-3^0.5 tan(75°)=2+3^0.5
tan(105°)=-2-3^0.5 tan(135°)=-1
tan(165°)=-2+3^0.5 tan(225°)=1