Question

5 sin 35°*cos 35°/ cos^2 10 °- sin^2 10°

Answer 1

$frac{5sin35*cos35}{cos^210-sin^210}= frac{2,5sin(35*2)}{cos(10*2)}= frac{2,5sin70}{cos20}= frac{2,5sin70}{cos(90-70)}= frac{2,5sin70}{sin70}=2,5$

Answer 2

Спасибо