化简 (sin^2(35°)-1/2)/cos10°cos80°

sin²1°+sin²2°+sin²3°+...+sin²89°化简 sin²1°+sin²2°+sin²3°+.+sin²89 化简sin^(a-30°)+sin^(a+30°)-sin^a化简sin^2(a-30°)+sin^2(a+30°)-sin^2a 1-2sin平方30°化简 计算：sin²1°+sin²2°+sin²3°...+sin²45°+sin²46°...+sin²89° 计算：sin²1°+sin²2°+sin²3°+...+sin²87°+sin²88°+sin²89° sin²1°+sin²2°+sin²3°+……+sin²87°+sin²88°+sin²89°= sin²1°+sin²2°+sin²3°+...+sin²88°+sin²89°+sin²90°=等于多少? 化简sin²α-2sinαcosα+1 化简Sin A + Sin 2A / 1+cos A + 1-2sin 22.5° 1/2-sin^215° 化简 (1-2sin@cos@)/(cos@^2-sin@^2)*(1+2sin@cos@)/(1-2sin@^2) 两分式相乘 化简[1-(sin^4 x-sin^2 xcos^2 x+cos^4 x)]/(sin^2 x)+3sin^2 x 化简[1-(sin^4x-sin^2cos^2x+cos^4x)/(sin^2)]+3sin^2x sin²1°+sin²2°+sin²3°+.+sin²89°= -1为什么? sin²1°+sin²2°+sin²3°……sin²89°=? sin²1°+sin²2°+sin²3°……sin²89°=