计算：sin²18°+cos45°×tan25°×tan65°+sin72°×cos18°
问题描述：
计算：sin²18°+cos45°×tan25°×tan65°+sin72°×cos18°
答
sin²18°+cos45°×tan25°×tan65°+sin72°×cos18°
=sin²18°+cos45°×tan25°×cot25°+sin72°×cos18°
=sin²18°+cos45°×1+cos18°×cos18°
=sin²18°+cos45°×1+cos²18°
=1+cos45°
=1+二分之根号二