196. Найдите sina, tga и ctga, если cosa = 1/4.

1. Найдем синус: $$\sin(\alpha) = \sqrt{1 - \cos^2(\alpha)} = \sqrt{1 - (\frac{1}{4})^2} = \sqrt{1 - \frac{1}{16}} = \sqrt{\frac{15}{16}} = \frac{\sqrt{15}}{4}$$.

2. Найдем тангенс: $$\operatorname{tg}(\alpha) = \frac{\sin(\alpha)}{\cos(\alpha)} = \frac{\sqrt{15}/4}{1/4} = \sqrt{15}$$.

3. Найдем котангенс: $$\operatorname{ctg}(\alpha) = \frac{1}{\operatorname{tg}(\alpha)} = \frac{1}{\sqrt{15}} = \frac{\sqrt{15}}{15}$$.