diff --git a/semester3/analysis-ii/cheat-sheet-rb/main.pdf b/semester3/analysis-ii/cheat-sheet-rb/main.pdf index 320b5d8..63ac78d 100644 Binary files a/semester3/analysis-ii/cheat-sheet-rb/main.pdf and b/semester3/analysis-ii/cheat-sheet-rb/main.pdf differ diff --git a/semester3/analysis-ii/cheat-sheet-rb/parts/05_diff.tex b/semester3/analysis-ii/cheat-sheet-rb/parts/05_diff.tex index 151df30..56e30cc 100644 --- a/semester3/analysis-ii/cheat-sheet-rb/parts/05_diff.tex +++ b/semester3/analysis-ii/cheat-sheet-rb/parts/05_diff.tex @@ -291,6 +291,19 @@ $$ & T_2f(y;x_0) = f(x_0) + \nabla f(x_0) \cdot y + \frac{1}{2} \Bigl( y^\top \cdot \textbf{H}_f(x_0) \cdot y\Bigr) \end{align*} +\begin{footnotesize} + \textbf{Example:} Approximate $f(x,y) = x\sqrt{y}$ at $f(1.1, 4.4)$ using $(1, 4)$. + \begin{align*} + T_1f(y;(1, 4)) &= f(1,4) + \nabla f(1, 4) \cdot (y_1-1, y_2-4) \\ + &= 2 + \begin{bmatrix} + 2 \\ + \frac{1}{4} + \end{bmatrix} \cdot (y_1-1, y_2-4) \\ + &= 2 + 2(y_1-1) + \frac{1}{4}(y_2-4) + \end{align*} + Thus $T_1f\bigl((1.1, 4.4); (1, 4)\bigr) = 2 + 2(1.1-1) + \frac{1}{4}(4.4-4) = 2.3$ +\end{footnotesize} + \method Calculating $T_kf(y;x_0)$ also yields $\textbf{H}_f$ for $k \geq 2$. \begin{align*} & T_2f((x_0,y_0);(x,y)) = \ldots + ax^2 + by^2 + cxy \\ diff --git a/semester3/analysis-ii/cheat-sheet-rb/parts/06_int.tex b/semester3/analysis-ii/cheat-sheet-rb/parts/06_int.tex index 552bd3c..1523e1f 100644 --- a/semester3/analysis-ii/cheat-sheet-rb/parts/06_int.tex +++ b/semester3/analysis-ii/cheat-sheet-rb/parts/06_int.tex @@ -217,12 +217,6 @@ $$ \newpage \subsection{Change of Variable} -\smalltext{This is to provide an Analogue of the Change of Variable in $\R$} -$$ - \int f\Bigl( g(x) \Bigr) g'(x)\ dx = \int f(y)\ dy -$$ - -\textbf{Prerequisites} \begin{footnotesize} $\bar{X},\bar{Y} \subset \R^n$ compact, $\varphi: \bar{X} \to \bar{Y}$ cont.\\ @@ -259,7 +253,7 @@ $$ \item Cylindrical Coordinates\\ \smalltext{ - $\varphi(r, \theta, z) = \bigl( r\cos(\theta),\ rsin(\theta),\ z \bigr) \quad \color{gray} \theta \in [0, \pi), \phi \in [0, 2\pi)$\\ + $\varphi(r, \theta, z) = \bigl( r\cos(\theta),\ r\sin(\theta),\ z \bigr) \quad \color{gray} \theta \in [0, \pi), \phi \in [0, 2\pi)$\\ $dxdydz = r\ dr\ d\theta\ dz$ } @@ -269,11 +263,33 @@ $$ $dxdydz = r^2\ \sin(\phi)\ dr\ d\theta\ d\phi$ } \end{enumerate} +\begin{footnotesize} + Corresponding Jacobians: + $$ + \textbf{J}_1 = \begin{bmatrix} + \cos(\theta) & -r\sin(\theta) \\ + \sin(\theta) & r\cos(\theta) \\ + \end{bmatrix} + \qquad + \textbf{J}_2 = \begin{bmatrix} + \cos(\theta) & -r\sin(\theta) & 0 \\ + \sin(\theta) & r\cos(\theta) & 0 \\ + 0 & 0 & z + \end{bmatrix} + $$ + $$ + \textbf{J}_3 = \begin{bmatrix} + \cos(\phi)\sin(\theta) & -r\sin(\phi)\sin(\theta) & r\cos(\phi)\cos(\theta) \\ + \sin(\phi)\sin(\theta) & r\cos(\phi)\sin(\theta) & r\sin(\phi)\cos(\theta) \\ + \cos(\theta) & 0 & -r\sin(\theta) + \end{bmatrix} + $$ +\end{footnotesize} % https://en.wikipedia.org/wiki/Spherical_coordinate_system#/media/File:3D_Spherical.svg -\begin{center} - \includegraphics[width=0.3\linewidth]{res/spherical-coords.png} -\end{center} +% \begin{center} +% \includegraphics[width=0.3\linewidth]{res/spherical-coords.png} +% \end{center} \newpage \subsection{Green's Theorem}