Question

ПОМОГИТЕ. ОПРЕДЕЛЁННЫЙ ИНТЕГРАЛ

Answer 1

$int_{1}^{2} frac{5dx}{ sqrt{5x - 1} } = int_{4}^{9} frac{1}{ sqrt{t} }dt = int_{4}^{9} {t}^{ - frac{1}{2} } dt = \ 5x - 1 = t, : dx = frac{1}{5} dt; \ x = 1: : t = 4, : x = 2:: t = 9 \ = 2 sqrt{t} |_{4}^{9} = 2 sqrt{9} - 2 sqrt{4} = 6 - 4 = 2$

Ответ: 2.