(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)=?

来源:学生作业帮助网 编辑:作业帮 时间:2024/03/29 18:46:28
(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)=?

(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)=?
(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)=?

(sin7°+cos15°sin8°)/(cos7°-sin15°sin8°)=?
(sin7+cos15sin8)/(cos7-sin15sin8)
====积化和差
=[sin7+(sin23-sin7)*0.5]/[cos7+(cos23-cos7)*0.5]
=(0.5sin7+0.5cos23)/(0.5cos7+0.5cos23)
====约分,和差化积
=(sin15*sin8)/(cos15*cos8)
====约分
=tan15(即tg15,我不知道你习惯用那种方式表示 正切)
====半角公式
=(1-cos30)/sin30
=2-3^(1/2) 就是2-根号3

0.2679491924