## Triangle area

I’ve just seen the following image on spikedmath.com: The second answers seem to be obviously the correct ones, right? Wrong. According to Heron’s formula you can calculate a triangles area like this: Let be the side lengths of the triangle. So the area of the first triangle is The area of the second one is [...]

I get a lot of data about my visitors which I would like to share. The following data is from 2012 of my domain martin-thoma.com. It was collected by Piwik. Note that I excluded my visits. Articles These articles had the most visitors: How to draw a finite-state machine Performance of Matrix multiplication in Python, [...]

## How can I clear gedit text search / replace history?

Start gconf-editor: Go to /apps/gnome-settings/gedit/history-gedit2_search_for_entry and /apps/gnome-settings/gedit/history-gedit2_replace_entry_with and remove the content there:

## Reflecting a point over a line

It’s astonishing how difficult it is to find a good explanation how to reflect a point over a line that does not use higher math methods. So here is my explanation: You have a point and a line and you want to get the point that got mirrored over . As you can see, you [...]

## Error correcting Codes

This blogpost is strongly related to this germand PDF of a pupils’ competition in which I have participated in 2008. Today, we have a lot of data that is stored or transferred in a binary way. Once in a while an error occurs and single bits get switched from 0 to 1 or the other [...]

## Nobel Prize in Physics 2009

Did you know how the election for a Nobel Prize works? Have you ever heard of a CCD? I guess you know fiberoptics? I’ve found this clip via forschungspreisen.de, a german blog about science. See also List of Nobel laureates List of Nobel laureates by country List of Nobel laureates by university affiliation

## How to search for mathematical symbols in LaTeX

Detexify The easiest way to search for a math symbol is Detexify. This webservices allows you to draw the symbol. It looks like this: Symbol tables Arrows \rightarrow \leftarrow \Rightarrow \Leftarrow \leftrightarrow \Leftrightarrow \nRightarrow \nrightarrow \leadsto \mapsto . . . . Greek \alpha \beta \gamma \delta \zeta \eta \theta \epsilon, \varepsilon \iota \kappa \lambda \mu [...]