sin(18°)sin(54°)sin(18°)*sin(54°) 不用计算器

sin(18°)sin(54°)sin(18°)*sin(54°) 不用计算器 sin sin sin(10°)+sin(50°)-sin(70°) =sin(10°)+sin(50°)-sin(70°) = sin 18°等于多少? sin?°≈0.6773? sin 15°是多少 sin²1°+sin²2°+sin²3°+.+sin²89 化简:sin^A*sin^A+sin(A-60°)*sin(A-60°)+sin(A+60°)* 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°= 计算：sin²1°+sin²2°+sin²3°...+sin²45°+sin²46°...+sin²89° 计算：sin²1°+sin²2°+sin²3°+...+sin²87°+sin²88°+sin²89° 求sin²10°+sin²20°+sin²40°+sin²50°+sin²70°+sin²80° sin²1°+sin²2°+sin²3°+……+sin²87°+sin²88°+sin²89°= sin²1°+sin²2°+sin²3°+...+sin²88°+sin²89°+sin²90°=等于多少? 化简sin^(a-30°)+sin^(a+30°)-sin^a化简sin^2(a-30°)+sin^2(a+30°)-sin^2a sin sin 为什么?sin 为什么? 比较大小(1)sin(-π/11)与sin(-π/17) (2)-sin(54π/7)与sin(-63π/8) (3)sin231°与cos260°