cos²25°+sin²25°-tan21°cot21°×tan45°

分类: 作业答案 • 2021-12-18 16:17:51

问题描述：

答

cos²25°+sin²25°-tan21°cot21°×tan45°
＝（cos²25°+sin²25°）-（tan21°cot21°）×tan45°
＝1-1×1
＝1-1
＝0

答

cos²25°+sin²25°-tan21°cot21°×tan45°
=1-1
=0

答

cos²25°+sin²25°-tan21°cot21°×tan45°
=1-1x1
=1-1
=0