diff --git a/semester3/analysis-ii/cheat-sheet-rb/main.pdf b/semester3/analysis-ii/cheat-sheet-rb/main.pdf index 63ac78d..99b50f6 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/06_int.tex b/semester3/analysis-ii/cheat-sheet-rb/parts/06_int.tex index 1523e1f..3c3bc78 100644 --- a/semester3/analysis-ii/cheat-sheet-rb/parts/06_int.tex +++ b/semester3/analysis-ii/cheat-sheet-rb/parts/06_int.tex @@ -105,6 +105,7 @@ $\forall x_1,x_2 \in X:$ Line seg. $x_1 \to x_2$ is in $X$\\ $$ \forall 1 \leq i \neq j \leq n: \frac{\partial f_i}{\partial x_j} = \frac{\partial f_j}{\partial x_i} \implies f \text{ conservative} $$ +\subtext{This is the most common way to prove/disprove $f$ being conservative.} \definition $\text{curl}(f) := \begin{bmatrix} \partial_y f_3 - \partial_z f_2 \\ @@ -199,7 +200,9 @@ $$ $$ \underset{x \to \infty}{\lim}\int_{[a,x]\times I}f(x,y)\ dxdy = \underbrace{\int_a^\infty \Biggl( \int_I f(x,y)\ dy \Biggr) dx}_\text{Order of Integration may change} $$ -If this Limit is equal for both orders of Integration: +\subtext{The improper integral on the right is simply a regular improper integral.} + +\smalltext{If this Limit is equal for both orders of Integration:} \definition \textbf{Improper Integral in $\R^2$} $$ @@ -243,57 +246,7 @@ $$ The change of variable is: $\displaystyle\int_{\bar{X}} f\Bigl( \varphi(x) \Bigr)\ dx = \frac{1}{\left\vert \det(\textbf{A}) \right\vert} \int_{\bar{Y}}f(y)\ dy$ \end{footnotesize} -\remark \textbf{Common Changes} -\begin{enumerate} - \item Polar Coordinates\\ - \smalltext{ - $\varphi(r, \theta) = \bigl(r\cos(\theta),\ r\sin(\theta)\bigr) \quad \color{gray} \theta \in [0, 2\pi) $\\ - $dxdy = r\ dr\ d\theta$ - } - - \item Cylindrical Coordinates\\ - \smalltext{ - $\varphi(r, \theta, z) = \bigl( r\cos(\theta),\ r\sin(\theta),\ z \bigr) \quad \color{gray} \theta \in [0, \pi), \phi \in [0, 2\pi)$\\ - $dxdydz = r\ dr\ d\theta\ dz$ - } - - \item Spherical Coordinates\\ - \smalltext{ - $\varphi(r, \theta, \phi) = (r\sin(\phi)\cos(\theta),\ r\sin(\phi)\sin(\theta),\ r\cos(\phi))$\\ - $dxdydz = r^2\ \sin(\phi)\ dr\ d\theta\ d\phi$ - } -\end{enumerate} -\begin{footnotesize} - Corresponding Jacobians: - $$ - \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} - $$ -\end{footnotesize} - -% https://en.wikipedia.org/wiki/Spherical_coordinate_system#/media/File:3D_Spherical.svg -% \begin{center} -% \includegraphics[width=0.3\linewidth]{res/spherical-coords.png} -% \end{center} - -\newpage \subsection{Green's Theorem} -\smalltext{An analogue of the Fundamental Theorem of Calculus in $\R^2$.} \definition \textbf{Simple Closed Parametrized Curve}\\ $\gamma: [a,b] \to \R^2$ closed param. curve s.t. @@ -301,8 +254,7 @@ $\gamma: [a,b] \to \R^2$ closed param. curve s.t. \item $\gamma(t) \neq \gamma(s)\quad$ unless $s = t$, or $\{s,t\} = \{a,b\}$ \item $\gamma'(t) \neq 0\quad \forall a < t < b$ \end{enumerate} -\subtext{Example: $\varphi(t) = \Bigl( x_0 + r\cos(t),\ y_0 + r\sin(t) \Bigr)$\\ -(A circle, traversed \textit{once}, i.e. for $0 \leq t \leq 2\pi$)} +\subtext{Example: $\varphi(t) = \Bigl( x_0 + r\cos(t),\ y_0 + r\sin(t) \Bigr)$} \begin{subbox}{Green's Theorem} \smalltext{$X \subset \R^2 \text{ compact with Boundary } \partial X = \displaystyle\underset{1 \leq i \leq n}{\bigcup} \gamma_i$ as above}\\ @@ -338,4 +290,127 @@ $$ $$ \text{Area}(X) = \int_X 1\ dxdy = \int_X \bigg(\partial_x f_y - \partial_y f_x \bigg) \ dxdy = \int_\gamma f(s)\ ds $$ -\end{footnotesize} \ No newline at end of file +\end{footnotesize} + +\subsection{Useful Parametrizations} + +\begin{footnotesize} + \textbf{Circle:} $x^2 + y^2 = r^2$ + $$ + \gamma: [0, 2\pi] \mapsto \begin{pmatrix} + r\cos(t) \\ + r\sin(t) + \end{pmatrix} + \qquad + \gamma: [0, 2\pi] \mapsto \begin{pmatrix} + r\cos(t) \\ + -r\sin(t) + \end{pmatrix} + $$ + \color{gray} Clockwise \& Counterclockwise \color{black} + + \textbf{Ellipsoid:} $\displaystyle\frac{x^2}{a^2}+\frac{y^2}{b^2}=1$ + $$ + \gamma: [0, 2\pi] \mapsto \begin{pmatrix} + a\cos(t) \\ + b\sin(t) + \end{pmatrix} + \qquad + \gamma: [0, 2\pi] \mapsto \begin{pmatrix} + a\cos(t) \\ + -b\sin(t) + \end{pmatrix} + $$ + \color{gray} Clockwise \& Counterclockwise \color{black} + + \textbf{Piecewise Continuous function:} $f(x)$ + $$ + \gamma: [a, b] \mapsto \bigl(t, f(t) \bigr) + $$ + + \textbf{Line Segment:} $(x_0,y_0,z_0) \to (x_1,y_1,z_1)$ + $$ + \gamma: [0, 1] \mapsto (1-t) + \begin{pmatrix} + x_0 \\ + y_0 \\ + z_0 + \end{pmatrix} + + t + \begin{pmatrix} + x_1 \\ + y_1 \\ + z_1 + \end{pmatrix} + $$ + \color{gray} This is simply linear interpolation in $\R^3$ \color{black} +\end{footnotesize} +\subsection{Common Changes} +\begin{footnotesize} + + \textbf{Polar Coordinates} ($\R^2$)\\ + $$ + \varphi(r, \theta) = \begin{pmatrix} + r\cos(\theta)\\ + r\sin(\theta) + \end{pmatrix} \qquad \color{gray} \theta \in [0, 2\pi) + $$ + $dxdy = r\ dr\ d\theta$ + + \textbf{Elliptic Coordinates} ($\R^2$)\\ + $$ + \varphi(r, \theta) = \begin{pmatrix} + ra\cos(\theta) \\ + rb\sin(\theta) + \end{pmatrix} \qquad \color{gray} \theta \in [0, 2\pi) + $$ + $dxdy = a\cdot b\cdot r\ dr\ d\varphi$ + + \textbf{Cylindrical Coordinates} ($\R^3$)\\ + $$ + \varphi(r, \theta, z) = \begin{pmatrix} + r\cos(\theta) \\ + r\sin(\theta) \\ + z + \end{pmatrix} + \qquad \color{gray} \theta \in [0, \pi), \phi \in [0, 2\pi) + $$ + $dxdydz = r\ dr\ d\theta\ dz$ + + \textbf{Spherical Coordinates} ($\R^3$)\\ + $$ + \varphi(r, \theta, \phi) = \begin{pmatrix} + r\sin(\phi)\cos(\theta) \\ + r\sin(\phi)\sin(\theta) \\ + r\cos(\phi) + \end{pmatrix} + \qquad \color{gray} \theta \in [0, \pi), \phi \in [0, 2\pi) + $$ + $dxdydz = r^2\cdot\sin(\phi)\ dr\ d\theta\ d\phi$ + + \textbf{Corresponding Jacobians}: + $$ + \textbf{J}_1 = \begin{bmatrix} + \cos(\theta) & -r\sin(\theta) \\ + \sin(\theta) & r\cos(\theta) \\ + \end{bmatrix} + \qquad + \textbf{J}_2 = \begin{bmatrix} + \cos(\theta) & -r\sin(\theta) & 0 \\ + \sin(\theta) & r\cos(\theta) & 0 \\ + 0 & 0 & z + \end{bmatrix} + $$ + $$ + \textbf{J}_3 = \begin{bmatrix} + \cos(\phi)\sin(\theta) & -r\sin(\phi)\sin(\theta) & r\cos(\phi)\cos(\theta) \\ + \sin(\phi)\sin(\theta) & r\cos(\phi)\sin(\theta) & r\sin(\phi)\cos(\theta) \\ + \cos(\theta) & 0 & -r\sin(\theta) + \end{bmatrix} + $$ + + % 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} +\end{footnotesize}