sin10°sin50°sin70°等于好多

来源：学生作业帮编辑：作业帮分类：数学作业时间：2024/05/10 19:53:11

sin10°*sin50°*sin70°等于好多

sin10°×sin50°×sin70°
= sin10°×sin50°×sin70°× cos10°/cos10°
= sin10°× cos10°×sin50°×sin70°/cos10°
= (1/2) × sin20°× sin50°× sin70°/cos10°
= (1/2) × sin20°× sin50°× cos20°/cos10°
= (1/4) × sin40°× sin50°/cos10°
= (1/4) × sin40°× cos40°/cos10°
= (1/8) × sin80°/cos10°
= (1/8) × sin80°/sin80°
= 1/8
【又
sin10°×sin50°×sin70°
=sin10°cos10°×cos20°×cos40°/cos10°
=.
再问： = (1/2) × sin20°× sin50°× sin70°/cos10°
= (1/2) × sin20°× sin50°× cos20°/cos10°
= (1/4) × sin40°× sin50°/cos10°
= (1/4) × sin40°× cos40°/cos10°
= (1/8) × sin80°/cos10°
= (1/8) × sin80°/sin80°
= 1/8为什么
再答： sin10°×sin50°×sin70°
=sin10°cos10°×cos20°×cos40°/cos10°
=1/2 sin20°×cos20°×cos40°/cos10°
=1/4 sin40°×cos40°/cos10°
=1/8 sin80°/cos10°
=1/8

sin10°*sin50°*sin70°等于好多 sin10°×sin50°×sin70°等于多少 sin10°sin50°-sin50°sin70°-sin70°sin10°=? sin10°sin30°sin50°sin70°=? 求值：sin10°sin50°sin70°sin80° 求值：sin10°sin50°·sin70° sin10°sin50°sin70° 怎样化简求值? 正弦函数求值sin10°*sin50°*sin70° sin10°×sin30°×sin50°×sin70°=（）.求详解, sin10°sin30°sin50°sin70°的值为（　　） sin70°cos20°-sin10°sin50°的值是多少?,麻烦给出过程求证Sin10° *Sin30° *Sin50° *Sin70° =1/16