5.3 The Fundamental Theorem of Calculus/10

Failed to parse (unknown function "\g"): {\displaystyle \begin{align} &\g(r)=\int_{0}^{r}\sqrt{x^2+4}dx\\[2ex] &\frac{d}{dx}\int_{0}^{r}\sqrt{x^2+4}dx\\[2ex] &\sqrt{x^2+4} \end{align} }