sin(45+&)sin(45-&)=1/6,90>&

sin(45+&)sin(45-&)=1/6,90>& 8sin(45+a)sin(45-a)=1,sin^4a-cos^4a= 计算：sin²1°+sin²2°+sin²3°...+sin²45°+sin²46°...+sin²89° 已知sin=1/4,45° sin(45度+a)= sin(45+a)cos(45+a)怎么得=1/2sin(90+2a)? 已知sin（45°+a）sin（45°-a）=-1/4,0° sin(45+x)sin(45-x)=1/6,x属于（90,180）,求sin4x 为什么sin-sin^2=1/4 sin 45度多少 求证:sin^2/(sin-cos) - (sin+cos)/(tan^2 -1) =sin+cos sin²0+sin²1+sin²2+……+sin²180= sin sin sin(sinx)/x,x 趋于0的极限sin(sin(x))/x=[sin(sin(x))/sin(x)]*sin(x)/x=1*1=1sin(sin(x))/sin(x)这一部我不明白阿 已知sin(45°-α)=-1/2,45° sin(45/2)/cos(45/2)=? 已知sin (30°) = 0.5,sin (45°) = 0.707,sin (40°)利用线性插值计算等于多少?