40×sin(45°+30°) ＝40×(√2/2×√3/2+√2/2×1/2)为什么等于这步啊?40×sin(45°+30°)＝40×(√2/2×√3/2+√2/2×1/2)为什么等于这步啊?.

计算:sin方10°+sin方20°+sin方30°+sin方40°+sin方50°+sin方60°+sin方70°+sin方80°+sin方90°= 已知sin (30°) = 0.5,sin (45°) = 0.707,sin (40°)利用线性插值计算等于多少? 求sin²10°+sin²20°+sin²40°+sin²50°+sin²70°+sin²80° 1.sin²40°+sin²50°等于多少1.sin²40°+sin²50°等于多少,2.如何证明sin（30°+α）=cos（60°-α） Sin(40+30)等于 尽快 我今天将就要!化简（计算）1、Sin²10°+Sin²20°+Sin²30°+Sin²40°+Sin²50°+Sin²60°+Sin²70°+Sin²80°+Sin²90°2、√（Sin44°-Cos44°)²3、√ 1-2Sim50°Cos50°4、tan41°*tan42°* sin【30°+45°】是多少, 计算：sin²1°+sin²2°+sin²3°...+sin²45°+sin²46°...+sin²89° 化简sin^(a-30°)+sin^(a+30°)-sin^a化简sin^2(a-30°)+sin^2(a+30°)-sin^2a COS 60°/SIN 30°—LAN 45°+SIN²45° (1)计算tan30°·sin²40°+tan30°·sin²50° sin100°* sin 140°如何推出等于sin80°* sin 40°, sin²40°+sin²50°+2-tan135°怎么算= （√2）/2·sin 45°+sin 30°=? f(x)=3sin(x-20°)+5sin(x+40°)的最大值 sin(α+30°)-sin(α-30°)/cosα sin(30°+x)-sin(30°-x)等于多少? sin(30°+β)-sin(30°-β)化简