∫(arctansqrt(x)/(sqrt(x)*(1+x)))dx
Замена переменной (arctg√x) = y - > 1/((1+x)*2√x)dx = dy т.к. (arctgx) ' = 1/(1+x^2) -> dx = dy*(2√x)*(1+x) -> ∫ ( ) dx = = ∫ (y/((√x)*(1+x))*dy*(1+x)*2√x) = ∫ 2ydy = y^2 + C = (arctg√x)^2 + C