sin6度

sin6° = 0.10452846326765

该式=sin6°sin42°sin66°sin78° =sin6°cos48°cos24°cos12° 上式乘以cos6°,得到cos6°*(sin6°cos48°cos24°cos12° )=1/2*sin12°cos48°cos24°cos12° =1/4*sin24°cos48°cos24°=1/8*sin48°cos48°=1/16*sin96°=1/16*cos6°所以原式=1/16

sin 12=2*sin6*cos6 =1/2*cos18-3^0.5/2*sin18-1/2*cos18 =sin18*cos6-sin6*cos18

sin6度等于a,sin平方6度等于多少 解 sin6°=a sin6°=(sin6°)=a

0.10452846

sin6sin42sin66sin78 =sin6cos12cos24cos48 =cos6sin6cos12cos24cos48/cos6 =sin12cos12cos24cos48/(2cos6) =sin24cos24cos48/(4cos6) =sin48cos48/(8cos6) =sin96/(16cos6) =cos6/(16cos6) =1/16

在x<10°时,sinx≈x,x单位为弧度,6°54′=6.9°=6.9/180rad=0.038333rad,所以sin6°54′=0.038333,用计算器求得sin6°54′=0.038324.

sin6sin42sin66sin78 =sin6(sin78=cos12)(sin78=cos24)(sin42=cos48) =sin6cos12*cos24cos48 =sin6cos6cos12*cos24cos48/cos6 =1/(2sin6cos61/2*2cos12*1cos24*2cos48/cos6 =1/2*1/2sin12*2cos12*cos24*cos48/cos6 =1/4*1/2sin24*cos24*cos48/cos6 =1/8*1/2sin48*2cos48/cos6 =1/16sin96/cos6(sin96=cos6) =1/16

0.0333271

0.1045284632676534713998341548025