2.Найти cosa, tga, если sina=\frac{1}{7}

Ответ: cosa = 0.98, tga = 0.14

1. Находим cosa:\[cos^2\alpha = 1 - sin^2\alpha = 1 - (\frac{1}{7})^2 = 1 - \frac{1}{49} = \frac{48}{49}\]\[cos\alpha = \sqrt{\frac{48}{49}} = \frac{\sqrt{48}}{7} = \frac{4\sqrt{3}}{7} ≈ 0.9897\]
2. Находим tga:\[tg\alpha = \frac{sin\alpha}{cos\alpha} = \frac{\frac{1}{7}}{\frac{4\sqrt{3}}{7}} = \frac{1}{4\sqrt{3}} = \frac{\sqrt{3}}{12} ≈ 0.1443\]

Ответ: cosa = 0.98, tga = 0.14