5.5 The Substitution Rule/39

Failed to parse (Conversion error. Server ("https://en.wikipedia.org/api/rest_") reported: "Cannot get mml. Server problem."): {\displaystyle {\begin{aligned}&\int \sec ^{3}(x)\tan(x)\,&u=\sec(x)&du=\sec(x)\tan(x)\,dx&\int \sec ^{3}(x)\tan(x)\,&&=\int u^{2}\,du&&=\end{aligned}}}