计算sin²25°+tan55°*tan35°+cos²25°-tan²30°
问题描述：
计算sin²25°+tan55°*tan35°+cos²25°-tan²30°
答
sin²25°+tan55°*tan35°+cos²25°-tan²30°
=sin²25°+cos²25°+tan55°*tan35°-tan²30°
=1+tan55°*tan35°-tan²30°
=1+cot35°*tan35°-tan²30°
=1+1-tan²30°
=2-1/3
=5/3