Question

35/cos^2 84градусов+cos^2 174 градусов помогиите:)

Answer 1

$displaystyle frac{35}{cos^284+cos^2174}= frac{35}{cos^2(90-6)+cos^2(180-6)}= \\= frac{35}{(cos(90-6))^2+(cos(180-6))^2}=\\= frac{35}{(sin6)^2+(-cos6)^2}= frac{35}{sin^26+cos^26}= frac{35}{1}=35$