导航 解：0no。m2Ws0Fan30ian60°3 (2)原式sin10°cos10°cos20°cos40 2c0s10° sin20°cos20°cos40°= sin40°cos40° 4c0S10° 8c0s10° sin80° c0s10° 1 16c0s10° =16c0s10° 16
导航
(3):sin50°(1+3tan10°)戶sin50°(1+V3sin10 导航 c0s10° =sin50°.cos10°+v3sin10° c0s10° 2in10:+2os10 =sin50° 2 c0s10° =sin50° 2sin40° 2sin40°cos40° sin80° c0S10° c0s10° c0s10° =1, sin80°V1+c0s20°=c0s10°V2c0s210°=V2c0s210°， :原式-1+cos20° 2c0s210° V2c0s210° 2c0s210° =V2
导航