Question

Найдите tg a если sin a = 5/8

Answer 1

$sin(a)^2+cos(a)^2=1$

$cos(a)=sqrt{1-sin(a)^2}$

$tan(a)=sin(a)/cos(a)$

$tan(a)=(5/8)/(sqrt{1-sin(a)^2})$

$tan(a)=5/(8*sqrt{1-25/64})=5/(8*sqrt{39/64})=5/sqrt{39}$