Question

sin5/3π+tan3/4π*cos8/3π=?求详解

Answer 1

sin5/3π=sin(2π-1/3π)=-sin1/3π=-√3/2

(1/3π=60°)

cos8/3π=cos(2π+2/3π)=cos2/3π=-1/2

(2/3π=120°)

tan3/4π=tan(π-1/4π)=-tan1/4π=-1

(1/4π=45°)

sin5/3π+tan3/4π*cos8/3π=-√3/2+(-1)(-1/2)=-(√3-1)/2=-0.366