5.5 The Substitution Rule/67

$\int _{e}^{e^{4}}{\frac {dx}{x{\sqrt {lnx}}}}$ = $\int _{1}^{4}{\frac {1}{u}}du$ = $\int _{1}^{4}u^{-1/2}du$ = Failed to parse (MathML with SVG or PNG fallback (recommended for modern browsers and accessibility tools): Invalid response ("Math extension cannot connect to Restbase.") from server "https://en.wikipedia.org/api/rest_v1/":): {\displaystyle \frac{u}^{1/2}{1/2}\bigg|_{1}^{4}} = ${2u}^{1/2}{\bigg |}_{1}^{4}$