vault backup: 2026-10-05 12:04:14

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ben committed 2026-10-05 12:04:14 -07:00
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@@ -15,4 +15,5 @@ $$\begin{gathered} 1<x<2 \\[1.5ex] x < y < x^2 \end{gathered}$$
We can think of finding the volume of the solid by using slices parallel to the $YZ$ plane. With the domain provided this area can be found with
$$ Area(x^*)=\int_{x}^{x^2}x^*ydy$$
Since $x$ is bound by $1<x<2$ the double integral to find the volume can be written as
$$\begin{gather} \int_{1}^2 \left[ \int_{x}^{x^2}xy \ dy \right] dx \\[1.5ex] \int_{1}^2 \left[ \int_{x}^{x^2} \frac{xy^2}{2} \right] dx \end{gather}$$
$$\begin{gather} \int_{1}^2 \left[ \int_{x}^{x^2}xy \ dy \right] dx \\[1.5ex] \int_{1}^2 \left[ \ \left.\frac{xy^2}{2} \right\vert_{x}^{x^2} \ \right] dx \\[1.5ex] \int_{1}^2 \left[ \frac{x}{2}((x^2)^2-(x)^2) \right] dx \\[1.5ex] \int_{1}^2 \frac{x^5}{2}-\frac{x^3}{2} dx \\[1.5ex] \left.\frac{x^6}{12}-\frac{x^4}{8} \right\vert_{1}^2 \\[1.5ex] \left( \frac{16}{3} - 2 \right) - \left( \frac{1}{12} - \frac{1}{8} \right) \end{gather}$$
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