2sin14°cos31°+sin17°=2sin14(cos14cos17-sin14sin17)+sin17=2sin14cos14cos17-2sin14sin14sin17+sin17=sin28cos17+sin17(1-2sin14sin14)=sin28cos17+sin17cos28=sin45=根纳衫游号洞销2/塌游2
cos(45°-α)等于什么
Simone
发布于 2023-10-16 16:03:08
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