Every year, thousands of students choose
12-09
12-09
12-09
12-09
12-09
12-09
12-09
12-09
12-09
In the center of the garden a large number of people
12-09
12-09
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题目,答案,用户
Every year, thousands of students choose
12-09
12-09
12-09
12-09
12-09
12-09
12-09
12-09
12-09
In the center of the garden a large number of people
12-09
12-09
12-09
题目[sin80-sin20]怎么变成2cos50sin30？可圈可点用户2021-02-08 11:11优质解答答案：sin80-sin20=sin(50+30)-sin(50-30)=√3/2sin50+1/2cos50-(
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题目
[sin80-sin20]怎么变成2cos50sin30？
可圈可点用户
2021-02-08 11:11
优质解答
sin80-sin20
=sin(50+30)-sin(50-30)
=√3/2sin50+1/2cos50-(√3/2sin50+1/2cos50)
=cos50
2cos50sin30=2*1/2*cos50=cos50
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