Lời giải cho tích phân bạn hỏi:
[tex]{I}=\int\frac{1}{x^3(\sqrt[7]{(x^7+1)^5})}}dx=\int\frac{x^5}{x^8(\sqrt[7]{(x^7+1)^5})}dx=\int\frac{1}{x^8\sqrt[7]{(\frac{x^7+1}{x^7})^5}}dx[/tex]
[tex]u=1+\frac{1}{x^7}\rightarrow{dx}=\frac{-7}{x^8}dx\rightarrow{dx}=\frac{-x^8}{7}du[/tex]
[tex]{I}=\frac{-1}{7}\int\frac{1}{\sqrt[7]{u^5}}du=-\frac{1}{2}\sqrt[7]{u^2}+C=-\frac{1}{2}\sqrt[7]{(1+\frac{1}{x^7})^2}+C[/tex]