Thus, here is an example of a function: [{1, 1}, {2, 1}, {3, 2}] This function consists of three pairs, whose first members are 1, 2 and 3. It is customary to give functions names, like f, g or h, and if we call this function f, we generally use the following notation to describe it: f(1) = 1, f(2) = 1, f(3) = 2. The first members of the pairs are called arguments and the whole set of them is called the domain of the function. Thus the arguments of f here are 1, 2 and 3, and the set consisting of these three numbers is its domain.
Road speed limits are used in most countries to set the maximum (or minimum in some cases) speed at which road vehicles may legally travel on particular stretches of road. Speed limits may be variable and in some places speeds are unlimited (e.g. on some Autobahn sections in Germany).
All of the roads in the US have a speed limit, the average being around 75 mph, with some areas in Texas and Utah reaching 80 mph. Road speed limits are used in most countries -- and are endorsed by the World Health Organization -- as a way to reduce road casualties. The highest speed limit ever introduced was in Abu Dhabi between 2005 and 2010 where the limit was set at 99 mph. The speed limit was reduced in 2011 to 87 mph. In Germany, some autobahns have no speed limit, but an advisory limit of 130 km/h (80 mph) was established in 2008.