计算:(sin7度+cos15度
(sin7度+cos15度sin8度)/(cos7度-sin15度sin8度)
=[sin(15-8)+cos15sin8]/[cos(15-8)-sin15sin8]
=[(sin15cos8-cos15sin8)+cos15sin8]
/[(cos15cos8+sin15sin8)-sin15sin8]
=sin15cos8/(cos15cos8)
=tan15
=(1-cos30)/sin30
=(1-√3/2)/(1/2)
=2-√3。
(sin7度+cos15度sin8度)/(cos7度-sin15度sin8度)
=[sin(15-8)+cos15sin8]/[cos(15-8)-sin15sin8]
=[(sin15cos8-cos15sin8)+cos15sin8]
/[(cos15cos8+sin15sin8)-sin15sin8]
=sin15cos8/(cos15cos8)
=tan15
=(1-cos30)/sin30
=(1-√3/2)/(1/2)
=2-√3。
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