sin15°+cos15°的值等于 _ .

问题描述:

sin15°+cos15°的值等于___ .

sin15°+cos15°=

2
2
2
sin15°+
2
2
cos15°)=
2
(sin15°cos45°+cos15°sin45°)
=
2
sin(15°+45°)=
2
sin60°=
2
×
3
2
=
6
2

故答案为:
6
2