sin5π/3=sin(2π-π/3)

sin5π/3=sin(2π-π/3) sin5/3π= ,cos5/3π sin（-π/3）+2sin5/3π+3sin2/3的值等于? 计算：sinπ／12 sin5π／12 (sin5π/12-sinπ/12)(sin5π/12+sinπ/12)的值 急! sin2/3π=? sin5/6π=? sin7/6π=? sin(-π/3）=? sin5π/6=1/2? sin5π /3为什么等于—√3/2? (sinπ/12)-(sin5π/12)+(2sinπ/8)(sin3π/8) sinπ/12-sin5π/12+2sinπ/8sin3π/8 sinπ /14*sin3π /14*sin5π /14 sin(-5π/3) 诱导公式我为什么算错?我是这样算的：=-sin5π/3=-sin（π+2π/3）=sin2π/3可是正确答案是sin1π/3,我到底是哪写错了? sinπ/18sin5π/18 sin（- 65π/18 sin之间为乘法sinπ/18sin5π/18 sin（- 65π/18sin之间为乘法 SIN5/6π 计算 sin5π/8*cos（7/8）π+sinπ/8-cos（3/8）π 三角函数值sin5π/4=sin(5π/4-2π)=?算不出来 要怎么算呢? sin5∏/3=? 已知sin(α+β)=3/5,sinβ=1/2,α+β,β均为锐角,求sinα的值.已知sin(α+β)=3/5,cos（α-β）=1/3,α+β,α-β均为锐角,求sin2α、cos2β.求[（sin5π/12）+（cos5π/12）]·[（sin5π/12）-（cos5π/12）]的值.求1+2cos²θ-cos2