$PreRead is a global variable whose value, if set, is applied to the text or box form of every input expression before it is fed to Mathematica.

Basic plotting functions. This plots a graph of sin(x) as a function of x from 0 to 2π. You can plot functions that have singularities. Mathematica will try to choose ...

Differentiating a known function gives an explicit result. Differentiating an unknown function f gives a result in terms of f'. Mathematica applies the chain rule for ...

Functions for grouping together elements of lists. Here is a list. This groups the elements of the list in pairs, throwing away the single element left at the end.

Mathematica allows you not only to export graphics and sounds, but also to import them. With Import you can read graphics and sounds in a wide variety of formats, and bring ...

You can use the keyboard to move the cursor forward or backward one character or one word at a time. You can also delete the character or word to the right or the left of the ...

Explicit representations of newlines and tabs in strings. This prints on two lines. In InputForm there is an explicit ∖n to represent the newline.

Testing for numeric quantities. Pi is a symbol, so Pi+3 is not explicitly a number. It does however have a numerical value.

You can tell a lot about what "type" of expression something is by looking at its head. Thus, for example, an integer has head Integer, while a list has head List. In a ...

Mathematica's ability to deal with symbolic expressions, as well as numbers, allows you to use it for many kinds of mathematics. Calculus is one example. With Mathematica, ...