Сравни

1. \(\sin \dfrac{10\pi}{9}\) и \(\sin \dfrac{8\pi}{7}\) ;

2. \(\cos (-5)\) и \(\cos (-6)\) .

Ответ: 1) [ \(\gt\) | \(\lt\) | \(=\) ]; 2) [ \(\gt\) | \(\lt\) | \(=\) ].