Question

найдите значение tg^2a если sin^2a=4/5

Answer 1

$sin^2a= \frac{4}{5}\\ tg^2a=?\\\\tg^2a= \frac{sin^2a}{cos^2a}\\cos^2=1-sin^2a=1- \frac{4}{5}= \frac{1}{5}\\\\tg^2a= \frac{4}{5} : \frac{1}{5}= \frac{4}{5} * \frac{5}{1}= 4$