diff --git a/semester2/analysis-i/cheat-sheet-jh/cheat-sheet-de.pdf b/semester2/analysis-i/cheat-sheet-jh/cheat-sheet-de.pdf index 6297d15..293c04b 100644 Binary files a/semester2/analysis-i/cheat-sheet-jh/cheat-sheet-de.pdf and b/semester2/analysis-i/cheat-sheet-jh/cheat-sheet-de.pdf differ diff --git a/semester2/analysis-i/cheat-sheet-jh/cheat-sheet-en.pdf b/semester2/analysis-i/cheat-sheet-jh/cheat-sheet-en.pdf index 1d7cada..1139a77 100644 Binary files a/semester2/analysis-i/cheat-sheet-jh/cheat-sheet-en.pdf and b/semester2/analysis-i/cheat-sheet-jh/cheat-sheet-en.pdf differ diff --git a/semester2/analysis-i/cheat-sheet-jh/parts/fields.tex b/semester2/analysis-i/cheat-sheet-jh/parts/fields.tex index d34e405..49c3e02 100644 --- a/semester2/analysis-i/cheat-sheet-jh/parts/fields.tex +++ b/semester2/analysis-i/cheat-sheet-jh/parts/fields.tex @@ -102,6 +102,8 @@ $\overline{a + bi} := a-bi$ (\tr{complex conjugate}{Komplexe Konjugation}); Transformation polar $\rightarrow$ normal: $r \cdot \cos(\phi) + r \cdot \sin(\phi)i$. Transformation normal $\rightarrow$ polar: $|z| \cdot e^{i \cdot \arcsin(\frac{b}{|z|})}$; +\textbf{\tr{Square root of negative number}{Quadratwurzel einer negativen Zahl}}: $\sqrt{-c} = ci$ + \begin{theorem}[]{\tr{Fundamental Theorem of Algebra}{Fundamentalsatz der Algebra}} \trLet $n \geq 1, n \in \N$ \tr{and let}{und sei} diff --git a/semester3/analysis-ii/cheat-sheet-jh/analysis-ii-cheat-sheet.pdf b/semester3/analysis-ii/cheat-sheet-jh/analysis-ii-cheat-sheet.pdf index bf84f3b..1571a40 100644 Binary files a/semester3/analysis-ii/cheat-sheet-jh/analysis-ii-cheat-sheet.pdf and b/semester3/analysis-ii/cheat-sheet-jh/analysis-ii-cheat-sheet.pdf differ diff --git a/semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/01_order-one.tex b/semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/01_order-one.tex index 360a1f6..54c10ee 100644 --- a/semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/01_order-one.tex +++ b/semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/01_order-one.tex @@ -1,12 +1,12 @@ \newsectionNoPB \subsection{Linear differential equations of first order} \rmvspace -\shortproposition Solution of $y' + ay = 0$ is of form $f(x) = z e^{-A(x)}$ with $A$ anti-derivative of $a$ +\shortproposition Solution of $y' + ay = 0$ is of form $f(x) = C e^{-A(x)}$ with $A$ anti-derivative of $a$ \rmvspace \shade{gray}{Imhomogeneous equation} \rmvspace \begin{enumerate}[noitemsep] \item Plug all values into $y_p = \int b(x) e^{A(x)}$ ($A(x)$ in the exponent instead of $-A(x)$ as in the homogeneous solution) - \item Solve and the final $y(x) = y_h + y_p$. For initial value problem, determine coefficient $z$ + \item Solve and the final $y(x) = y_h + y_p$. For initial value problem, determine coefficient $C$ \end{enumerate} diff --git a/semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/02_constant-coefficient.tex b/semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/02_constant-coefficient.tex index 1ddf1a4..46b9b0a 100644 --- a/semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/02_constant-coefficient.tex +++ b/semester3/analysis-ii/cheat-sheet-jh/parts/diffeq/linear-ode/02_constant-coefficient.tex @@ -5,11 +5,14 @@ The coefficients $a_i$ are constant functions of form $a_i(x) = k$ with $k$ cons \shade{gray}{Homogeneous Equation}\rmvspace \begin{enumerate}[noitemsep] \item Find \bi{characteristic polynomial} (of form $\lambda^k + a_{k - 1} \lambda^{k - 1} + \ldots + a_1 \lambda + a_0$ for order $k$ lin. ODE with coefficients $a_i \in \R$). - \item Find the roots of polynomial. The solution space is given by $\{ z_j \cdot x^{v_j - 1} e^{\gamma_i x} \divides v_j \in \N, \gamma_i \in \R \}$ where $v_j$ is the multiplicity of the root $\gamma_i$. - For $\gamma_i = \alpha + \beta i \in \C$, we have $z_1 \cdot e^{\alpha x}\cos(\beta x)$, $z_2 \cdot e^{\alpha x}\sin(\beta x)$, representing the two complex conjugated solutions. + \item Find the roots of polynomial. The solution space is given by $\{ C_j \cdot x^{v_j - 1} e^{\gamma_i x} \divides v_j \in \N, \gamma_i \in \R \}$ + where $v_j$ is the multiplicity of the root $\gamma_i$ and $C_j$ is a constant. + For $\gamma_i = \alpha + \beta i \in \C$, we have $C_1 \cdot e^{\alpha x}\cos(\beta x)$, $C_2 \cdot e^{\alpha x}\sin(\beta x)$, + representing the two complex conjugated solutions. \end{enumerate} - \rmvspace + +The homogeneous equation will then be all the elements of the set summed up.\\ \shade{gray}{Inhomogeneous Equation}\rmvspace \begin{enumerate}[noitemsep] \item \bi{(Case 1)} $b(x) = c x^d e^{\alpha x}$, with special cases $x^d$ and $e^{\alpha x}$: