计算,sin(π/12)-sin(5π/12)+2sin(π/8)sin(3π/8)

计算,sin(π/12)-sin(5π/12)+2sin(π/8)sin(3π/8) 计算:sin(π/12)sin(5π/12)要用二倍角与半角的公式 计算：sinπ／12 sin5π／12 计算cosπ/12*sinπ/12 计算sin(arcsin3/5+π/4) 计算sin(π/10)x sin (13π/10) 计算:sin(兀)/(12) 乘以 sin(5兀)/(12) sin(5π/12)= sin(-5π/12)是多少 计算:sin[arc*sin(3/5)+arc*sin(7/18)] 计算arccos(sin 3π/5)的值 已知sin a=2cos a 计算⑴（sinα+2cosα)/(5cosα-sinα) ⑵tan(α+π/4) 已知sina=4/5 a∈(π/2,π)计算sin(a+6/π)+sin(a-6/π) 已知sin(π+a)=-1/2,计算:sin(5π-a)和cos(a-（3π/2）） 已知sin（π＋α）＝－1/2,计算sin（5π－α）的值 化简sin(4π-a)*sin(5π-a)=? sin(α-π/4)=12/13,sinα= sin(-5π/3)等于