How can i make this program calculate my age correctly? (probably simple, I'm a beginner)
How do I calculate someone's age based on a DateTime type birthday?
How many combinations are possible in the game tic-tac-toe (Noughts and crosses)?  So for example a game which looked like: (with positions 1-9)  A1   --   B1  A2   --   B2  A3   --   --   [1][3][4][6][7] would be one combination Replacements for switch statement in Python? I want to write a function in Python that returns different fixed values based on the value of an input index.    In other languages I would use a switch or case statement, but Python does not appear to have a switch statement.  What are the recommended Python solutions in this scenario? I heard that there was a twitter bot which automatically posted questions and asked for answers for specific questions on every site. How do they work? Is there an algorithm for doing this or is it purely random? I know that it doesn't tweet closed questions, but that's it. How to install Oracle 18c (Enterprise Edition) on Ubuntu 18.04? This question is unanswered since Oracle 18c has been released. Except Ubuntu Linux platform, most of the other Linux platform supports Oracle 18c installation. I, myself, tested this on CentOS 7 and oracle 18c got installed without any glitch!  It is unfortunate that Oracle Corporation has not documented the installation procedure particularly for Ubuntu Linux platform, nevertheless one good thing is that the image file db_home.zip is a generic one, installable across all Linux platforms.    So how can I install Oracle 18c (Enterprise Edition) on Ubuntu 18.04? When a user votes to close a question (for whatever reason), it would helpful to receive a notification (in the inbox) when the question is edited (either the text, tags, if it closes then is re-opened) so that the user can then modify his or her vote if the question is properly adjusted. Exclude from * in command line What, precisely, is a confidence interval? Limit of derivative is zero. Does it imply a limit for f(x)? Keytool Signing Problem: Keystore was tampered with, or password was incorrect Why is the potential energy equal to the negative integral of a force? I'm considering the ring $\mathbb{Z}[\sqrt{-n}]$, where $n\ge 3$ and square free. I want to see why it's not a UFD.   I defined a norm for the ring by $|a+b\sqrt{-n}|=a^2+nb^2$. Using this I was able to show that $2$, $\sqrt{-n}$ and $1+\sqrt{-n}$ are all irreducible. Is there someway to conclude that $\mathbb{Z}[\sqrt{-n}]$ is not a UFD based on this? Thanks. Command to display and execute code (math formulae) Similar to  I would like to have a command to display and execute code. The code should be displayed with the listings package.  For example something like  \documentclass{scrartcl} \usepackage{amsmath,listings} \newcommand*{\codeExample}[1]{Code: \lstinline!\string{#1}! yields #1} \begin{document}   \codeExample{$\lVert a\rVert$} \end{document}   should for best of cases display $\lVert a \rVert$ as verbatim (\lstinline!...!) code and after that the rendered math code. Is something like that possible? The code above yields several mistakes. I think I miss something to avoid #1 being tokenised? Differences Between Row Echelon and Reduced Row Echelon Let $$A =\begin{bmatrix} 1&amp;3&amp;-6&amp;2\\5&amp;12&amp;-24&amp;7\\9&amp;15&amp;-30&amp;6\end{bmatrix}$$  $$RREF(A) =\begin{bmatrix} 1&amp;0&amp;0&amp;-1\\0&amp;1&amp;-2&amp;-1\\0&amp;0&amp;0&amp;0\end{bmatrix}$$ $$REF(A) =\begin{bmatrix} 1&amp;3&amp;-6&amp;2\\0&amp;1&amp;-2&amp;1\\0&amp;0&amp;0&amp;0\\\end{bmatrix}$$  Now, provided this information, it can be found that the basis for the nullspace of $A$ using the $RREF(A)$ is: $$\begin{pmatrix} \begin{bmatrix} 0\\2\\1\\0 \end{bmatrix}, \begin{bmatrix} 1\\-1\\0\\1 \end{bmatrix}\end{pmatrix}$$  Using the $REF(A)$ the "basis" for the nullspace is:  $$\begin{pmatrix} \begin{bmatrix} 6\\2\\1\\0 \end{bmatrix}, \begin{bmatrix} -2\\-1\\0\\1 \end{bmatrix}\end{pmatrix}$$  Is the "basis" that I provided for the $REF(A)$ actually a basis? How does the  $REF$ and $RREF$ of a matrix differ? I've just started to play with pgfplot. I'm trying to prepare a plot like to following   \begin{figure}[h] \centering \begin{tikzpicture} \begin{axis}[minor tick num=1,  axis x line=middle, axis y line=middle, xlabel=$k$, ylabel=$\omega$, ymin=0,xmin=-2,ymax=60] \addplot[blue,domain=0:5, line width=1.5pt] {x^2+25}; \addplot[orange,domain=0:5,line width=1pt]{3*x+22.75}; \addplot[cyan,domain=0:1.5, line width=1pt,dashed]{18.166*x}; \node[coordinate,pin=right:{$v_{\phi}=\frac{\omega}{k}$}]     at (axis cs:1,17) {}; \node[coordinate,pin=right:{$v_{g}=\frac{d\omega}{dk}$}]     at (axis cs:2.5,30) {}; \node[coordinate,pin=left:{dispersion relation}]     at (axis cs:4.5,47) {}; \end{axis} \end{tikzpicture} \caption{Wave dispersion relation with phase and group velocity} \label{fig:2} \end{figure}   What I would like to do is dropping the x-y tick labels so that we just maintaing the x-y title. How can I obtain it? Can Gmail automatically base "send from" address on the "to" address? What is the difference between Python's list methods append and extend? Does a first generation iPod touch have the ability to download apps and use emojis? I am getting a 1st gen iPod touch for a friend and I was wondering if you can download like apps and games on it and if it has emojis? It would help to get an answer before I buy it! Space ship manned by only AI returns home to a different earth, back in time Show that for any prime $ p $, there are integers $ x $ and $ y $ such that $ p|(x^{2} + y^{2} + 1) $. Does there exist a continuous function such that f(x) is rational for every irrational x, and f(x) is irrational for every rational x? Does there exist a continuous function such that f(x) is rational for every irrational x, and f(x) is irrational for every rational x? I can think of examples where this would be true, but I'm having a lot of trouble with the continuity.