Mathematica: Derivatives involving absolute values

Use ComplexExpand. e.g. D[ComplexExpand@Abs[x-1],x]

Source: http://mathematica.stackexchange.com/questions/47100/derivative-of-the-absolute-value-function-in-mathematica-looks-very-different-fr

Interesting Reads: Nick Brown smelled bull

http://narrative.ly/pieces-of-mind/nick-brown-smelled-bull/

Interesting Reads: Making of Crash Bandicoot

http://all-things-andy-gavin.com/2011/02/02/making-crash-bandicoot-part-1/

Andy Gavin and Jason Rubin, creators of the original Crash Bandicoot released in 1996, details the makings of the game, over a series of 13 blog posts.

Product Review: Rotating 360 Leather Case for Samsung Galaxy Tab S 8.4 SM-T700/SM-T705

Bought from here.

Pros:
- Does its job, protects the Samsung galaxy tab.
- Cheap, about $12

Cons:
- Rotating 360 isn't as useful as it sounds. No real need to put in portrait mode. The fact that it can be put it both landscape and portrait mode makes it less structurally sound.
- It has two slots to hold the tablet. The most upright position isn't very stable. It has fallen down more than once when playing games in this position.
- Inside cover gets dirty easily. So when you close the cover, the screen itself will also get dirty.
- After two and a half months of use, fabric has started to wear and tear out at the part where the cover bends.

Additional comment: To keep the cover on the tablet, an elastic strap is used to hold it in place. This mechanism slightly bends the cover at the edges.