Question

дано: sin a=0,5
надо найти: cos a, tg a, ctg a

Answer 1

$sin alpha =0.5= frac{1}{2} \ \ cos alpha = sqrt{1-sin^2 alpha }= sqrt{1-( frac{1}{2} )^2}= sqrt{1- frac{1}{4} }= sqrt{ frac{3}{4} }= frac{ sqrt{3} }{2} \ \ tg alpha = frac{sin alpha }{cos alpha } = frac{1}{2}: frac{ sqrt{3} }{2}= frac{1}{2}* frac{ 2 }{sqrt{3}}= frac{1}{sqrt{3}}= frac{sqrt{3}}{3}$

$ctg alpha = frac{cos alpha }{sin alpha } = frac{ sqrt{3} }{2}: frac{1 }{2}= frac{ sqrt{3} }{2}* frac{2 }{1}= sqrt{3}$