Question

cos15°+sin75°的值是______．

Answer 1

cos15°+sin75°=cos（45°-30°）+sin（45°+30°）=cos45°cos30°+sin45°sin30°+sin45°cos30°+cos45°sin30°
=

2

2

×

3

2

+

2

2

×

1

2

+

2

2

×

3

2

+

2

2

×

1

2

=

6 + 2

2

．
故答案为：

6 + 2

2

．