问题
填空题
sin45°cos15°+cos225°•sin15°的值为______.
答案
∵sin45°cos15°+cos225°•sin15°
=
| ||
2 |
| ||
2 |
=cos(45°+15°)
=
1 |
2 |
故答案为:
1 |
2 |
sin45°cos15°+cos225°•sin15°的值为______.
∵sin45°cos15°+cos225°•sin15°
=
| ||
2 |
| ||
2 |
=cos(45°+15°)
=
1 |
2 |
故答案为:
1 |
2 |