求值:cos5π/8cosπ/8=
来源:学生作业帮 编辑:作业帮 分类:数学作业 时间:2024/05/12 05:43:53
求值:cos5π/8cosπ/8=
cos(5π/8+π/8)=cos5π/8cosπ/8-sin5π/8sinπ/8=-√2/2
cos(5π/8-π/8)=cos5π/8cosπ/8+sin5π/8sinπ/8=0
两式相加2cos5π/8cosπ/8=-√2/2
cos5π/8cosπ/8=-√2/4
很高兴为您解答,【学习宝典】团队为您答题.请点击下面的【选为满意回答】按钮,
再问: 请问cos5π/8cosπ/8-sin5π/8sinπ/8=如何为-√2/2 cos5π/8cosπ/8+sin5π/8sinπ/8=如何为0 谢谢
再答: cos5π/8cosπ/8-sin5π/8sinπ/8=cos(5π/8+π/8)=cos(6π/8)=cos(3π/4)=-√2/2 同理cos5π/8cosπ/8+sin5π/8sinπ/8=cos(5π/8-π/8)=cos(π/2)=0
cos(5π/8-π/8)=cos5π/8cosπ/8+sin5π/8sinπ/8=0
两式相加2cos5π/8cosπ/8=-√2/2
cos5π/8cosπ/8=-√2/4
很高兴为您解答,【学习宝典】团队为您答题.请点击下面的【选为满意回答】按钮,
再问: 请问cos5π/8cosπ/8-sin5π/8sinπ/8=如何为-√2/2 cos5π/8cosπ/8+sin5π/8sinπ/8=如何为0 谢谢
再答: cos5π/8cosπ/8-sin5π/8sinπ/8=cos(5π/8+π/8)=cos(6π/8)=cos(3π/4)=-√2/2 同理cos5π/8cosπ/8+sin5π/8sinπ/8=cos(5π/8-π/8)=cos(π/2)=0
求值cos5π/8*cosπ8
不查表求值:cos5π/12·sinπ/12=
cos5/12πcosπ/12+cosπ/12sinπ/6=?
反三角函数求值arccos(cos5π/4)=?arctan(tan4π/3)=?arcsin(sin6)=?
(sin5π/12-sinπ/12)(cos5π/12+cosπ/12)=?
计算cos5∏/8 * cos∏/8 的值
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cos5π/12=sinπ/12
计算cos5分之π+cos5分之2π+cos5分之3π+cos5分之4π
帮我解,证明恒等式(cos平方5π/12)+(cos平方π/12)+(cos5π/12)(cosπ/12)=5/4
数学,证明恒等式(cos平方5π/12)+(cos平方π/12)+(cos5π/12)(cosπ/12)=5/4.
(sin5π/12+cos5π/12)(sinπ/12-cosπ/12)