Вычисли

1. \(\cos10\degree \cos30\degree \cos50\degree \cos70\degree \) ;

2. \(\cfrac{\sin20\degree \sin40\degree \sin60\degree \sin80\degree }{\sin10\degree \sin30\degree \sin50\degree \sin70\degree }\) .

Ответ: 1) [ ]; 2) [ ].