"Values for Symbols" discussed how you can use transformation rules of the form x->value to replace symbols by values. The notion of transformation rules in Mathematica is, ...

In many kinds of numerical computations, it is convenient to introduce approximate functions. Approximate functions can be thought of as generalizations of ordinary ...

Mathematica supports many formats, with many subformats, variants, and options.

Invisible characters. In the input there is an invisible comma between the 1 and 2. Here there is an invisible space between the x and y, interpreted as multiplication.

Mathematica's unified symbolic document architecture makes it possible to have flowing text contain any kind of object—including math, graphics or dynamic elements.

"Defining Functions" discusses how you can define functions in Mathematica. In a typical case, you would type in f[x_]=x^2 to define a function f. (Actually, the definitions ...

As the basis for many other special functions, Mathematica supports efficient arbitrary-precision evaluation of gamma functions, as well as an extensive web of relations and ...

Delete[expr, n] deletes the element at position n in expr. If n is negative, the position is counted from the end. Delete[expr, {i, j, ...}] deletes the part at position {i, ...

Mathematica supports zeta and polylogarithm functions of a complex variable in full generality, performing efficient arbitrary-precision evaluation and implementing extensive ...

Many programs you write will involve operations that need to be iterated several times. Nest and NestList are powerful constructs for doing this. Applying functions of one ...