Question

Дано: cos a =5/6 найдиде sin a ,tg a

Answer 1

$sin alpha = sqrt{1-cos^{2} alpha }= sqrt{1- frac{25}{36} } = frac{ sqrt{11} }{6} \ tg alpha = frac{sin alpha }{cos alpha } = frac{ frac{ sqrt{11} }{6} }{ frac{5}{6} } = frac{ sqrt{11} }{5}$