Mathematica normally assumes that variables which appear in equations can stand for arbitrary complex numbers. But when you use Reduce, you can explicitly tell Mathematica ...

PositiveDefiniteMatrixQ[m] tests whether m is a positive definite matrix.

Converting between numbers and lists or strings of digits. Here is the list of base 16 digits for an integer. This gives a list of digits, together with the number of digits ...

NSolve[expr, vars] attempts to find numerical approximations to the solutions of the system expr of equations or inequalities for the variables vars. NSolve[expr, vars, ...

ConditionalExpression[expr, cond] is a symbolic construct that represents the expression expr when the condition cond is True.

Prefix[f[expr]] prints with f[expr] given in default prefix form: f@expr. Prefix[f[expr], h] prints as hexpr.

Each version of Mathematica comes with a variety of standard extra packages that provide specific additional functionality. The specific code of these packages can be ...

These "How tos" give step-by-step instructions for common tasks related to solving differential equations in Mathematica .

Chini equations are a generalization of Abel and Riccati equations. This solves a Chini equation.