5.5 The Substitution Rule/67

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 \int_{e}^{e^4}\frac{dx}{x\sqrt{lnx}} = $\int _{1}^{4}{\frac {1}{u}}du$