sin15°+cos15°的值等于 _ .
问题描述:
sin15°+cos15°的值等于___ .
答
sin15°+cos15°=
(
2
sin15°+
2
2
cos15°)=
2
2
(sin15°cos45°+cos15°sin45°)
2
=
sin(15°+45°)=
2
sin60°=
2
×
2
=
3
2
.
6
2
故答案为:
6
2