问题
填空题
|
答案
cos15°+sin15°=2( 3
sin15°+3 2
cos15°)=2(sin15°cos30°+cos15°sin30°)1 2
=2sin(15°+30°)=2sin45°=2×
=2 2
.2
故答案为:
.2
|
cos15°+sin15°=2( 3
sin15°+3 2
cos15°)=2(sin15°cos30°+cos15°sin30°)1 2
=2sin(15°+30°)=2sin45°=2×
=2 2
.2
故答案为:
.2