sin²(π/8)-cos²(π/8)求值
8sin(π/32)cos(π/32)cos(π/16)cos(π/8),求值
求值:sin(π/12)+cos(π/12)
不用计算器求值sinπ\8 cosπ\8=sin^2 π\12-cos^2 π\12=化简:(cosx+sinx)^2=
已知6sin²α+sinαcosα-2cos²α=0,α∈(π/2,π),求值
求值cos5π/8*cosπ8
求值:⑴sin(-19π/3)*cos(19π/6)
sin²π/8 -cos²π/8
数学的三角公式求值题sin²15º-cos²15º ;sin²﹙π÷1
sin^a+cos^(π/6+a)+1/2sin(2a+π/6)求值
化简求值sin(-20/3π)cos(43/6π)+sin(35/6π)cos-(17/3π)
求SINπ/64 COSπ/64 COSπ/32 COSπ/16 COSπ/8
求下列各式的值.第一题sin 15°cos 15° 第二题cos²π/8-sin²π/8