求tan1° × tan2°×tan3°···tan87°×tan88°×tan89°的值 麻烦写出计算的过程,
问题描述:
求tan1° × tan2°×tan3°···tan87°×tan88°×tan89°的值 麻烦写出计算的过程,
答
tan1°×tan89°=tan1°×cot1°=1 tan2°×tan88°=tan2°×cot2°=1 .tan44°×tan46°=tan44°×cot44°=1 则tan1° × tan2°×tan3°···tan87°×tan88°×tan89°=tan45°=1