Skip to main content
Mathematics LibreTexts

10.7: Change of Variables in Multiple Integrals

  • Page ID
    144356
  • \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    \( \newcommand{\id}{\mathrm{id}}\) \( \newcommand{\Span}{\mathrm{span}}\)

    ( \newcommand{\kernel}{\mathrm{null}\,}\) \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\) \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\) \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\id}{\mathrm{id}}\)

    \( \newcommand{\Span}{\mathrm{span}}\)

    \( \newcommand{\kernel}{\mathrm{null}\,}\)

    \( \newcommand{\range}{\mathrm{range}\,}\)

    \( \newcommand{\RealPart}{\mathrm{Re}}\)

    \( \newcommand{\ImaginaryPart}{\mathrm{Im}}\)

    \( \newcommand{\Argument}{\mathrm{Arg}}\)

    \( \newcommand{\norm}[1]{\| #1 \|}\)

    \( \newcommand{\inner}[2]{\langle #1, #2 \rangle}\)

    \( \newcommand{\Span}{\mathrm{span}}\) \( \newcommand{\AA}{\unicode[.8,0]{x212B}}\)

    \( \newcommand{\vectorA}[1]{\vec{#1}}      % arrow\)

    \( \newcommand{\vectorAt}[1]{\vec{\text{#1}}}      % arrow\)

    \( \newcommand{\vectorB}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vectorC}[1]{\textbf{#1}} \)

    \( \newcommand{\vectorD}[1]{\overrightarrow{#1}} \)

    \( \newcommand{\vectorDt}[1]{\overrightarrow{\text{#1}}} \)

    \( \newcommand{\vectE}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash{\mathbf {#1}}}} \)

    \( \newcommand{\vecs}[1]{\overset { \scriptstyle \rightharpoonup} {\mathbf{#1}} } \)

    \( \newcommand{\vecd}[1]{\overset{-\!-\!\rightharpoonup}{\vphantom{a}\smash {#1}}} \)

    1. Find the Jacobian of the transformation \(x = r\cos \theta\), \(y = r\sin \theta\).
       
    2. Find the Jacobian of the transformation \(x = \rho\sin\phi\cos\theta\), \(y = \rho\sin\phi\sin\theta\), \(z = \rho\cos\phi\).
       
    3. Let \(R\) be the region in the first quadrant bounded by \(x = 1\), and \(y = x\). Evaluate \(\displaystyle \iint_R (x + y)\ dA\) using the transformation \(u = x+y\), \(v = x-y\).
       
    4. Let \(R\) be the triangular region with vertices \((0, 0)\), \((2, 0)\), and \((1, 1)\). Evaluate \(\displaystyle \iint_R \sin\left(\frac{x+y}{2}\right)\cos\left(\frac{x-y}{2}\right)\ dx\,dy\) by making the change of variables \(u = \frac{1}{2}(x+y)\), \(v = \frac{1}{2}(x-y)\).
       
    5. Let \(R\) be the parallelogram with vertices \((0, 0)\), \((3, 3)\), \((7, 3)\), and \((4, 0)\). Evaluate \(\displaystyle \iint_R  y(x - y)\ dA\) using the transformation \(u = x-y\), \(v = y\).
       
    6. Let \(R\) be the region in the first quadrant enclosed by \(y = x\), \(y = 3x\), \(xy = 1\), and \(xy = 4\). Evaluate \(\displaystyle \iint_R xy^3\ dx\,dy\) by making the change of variables \(u = xy\), \(v = y/x\).
       
    7. Let \(R\) be the region bounded by the ellipse \(x^2 + 25y^2 = 1\). Evaluate \(\displaystyle \iint_R \sqrt{x^2 + 25y^2}\ dA\) using the transformation \(u = x\), \(v = 5y\).
       
    8. Let \(E\) be the solid enclosed by the ellipsoid \(\dfrac{x^2}{a^2} + \dfrac{y^2}{b^2} + \dfrac{z^2}{c^2} = 1\). Evaluate \(\displaystyle \iiint_E \ dV\) using the transformation \(u = \dfrac{x}{a}\), \(v = \dfrac{y}{b}\), \(w = \dfrac{z}{c}\).

    10.7: Change of Variables in Multiple Integrals is shared under a not declared license and was authored, remixed, and/or curated by LibreTexts.

    • Was this article helpful?