Question

интеграл 5dx/cos^2x ​

Answer 1

$\int\limits^{\frac{\pi}{4}}_{0} {\frac{5dx}{\cos^2{x}} = 5\int\limits^{\frac{\pi}{4}}_{0} {\frac{dx}{\cos^2{x}}  = 5 (\tan {\frac{\pi}{4}- 0)=5(1-0)=5$