Question

Помогите
$tg^2 alpha - ? \ 6sin^2 alpha +13cos^2 alpha =10$

Answer 1

$a) tg^2alpha=frac{sin^2alpha}{cos^2alpha} \\b) 6sin^2alpha+13cos^2alpha=10 \6(1cos^2alpha)+13cos^2alpha=10 \6-6cos^2alpha+13cos^2alpha=10 \7cos^2alpha=4 \cos^2alpha=frac{4}{7} \cosalpha=pm sqrtfrac{4}{7} \alpha=pm arccossqrtfrac{4}{7}+2pi n,n in Z ili alpha=pm arccos-sqrtfrac{4}{7}+2pi n,n in Z \OTBET:alphain{pm arccossqrtfrac{4}{7}+2pi n; pm arccos-sqrtfrac{4}{7}+2pi n}, nin Z$

Answer 2

Чуток исправил ошибки*