cos^2 80°+sin^2 50°-sin190°cos320°要求值.

sin^2 30°+cos()=1 3-cos 20°/2-sin ^2 80°等于 sin^2 80°为什么等于 cos^2 10°? (cos^2 10°-cos^2 80°)+sin^2 20° (cos 10)^2+(cos 50)^2-sin 40 * sin 80 怎么算 利用和差角公式化简 (2)sin(π/3+α)+sin(π/3-α)(2)sin(π/3+α)+sin(π/3-α)(3)cos(π/4+α)-cos(π/4-α)(4)cos(60°+α)+cos(60°-α)(5)sin(α-β)cosβ+cos(α-β)sinβ(6)cos(α+β)cosβ+sin(α+β)sinβ 化简 （1+sin a+ cos a)(sin a/2 - cos a/2) / √(2+2cos a)(180° cos^2 80°+sin^2 50°-sin190°cos320°要求值. cos^2 80°+sin^2 50°-sin190°cos320° 化简：(1)(cos²10°-cos²80°)²+cos²70°=? (2)(sinα-cosα)²+sin4α/2cos2α= 2sin@+cos@等于? sin^2(20)-sin^2(25)sin(20)+cos^2(50)+cos^2(25)sin20 sin(10°)+sin(20°)cos(50°)求值 (cos^2)15°+(sin^2)15°等于多少 Sin^2 45°+cos^2 45°=? 计算cos^2*105°-sin^2*105° cos^2 22.5 °- sin^2 22.5° cos^2 15°-sin^2 15°的值