FresnelC (Built-in Mathematica Symbol)

FresnelC[z] gives the Fresnel integral C(z).

FresnelS (Built-in Mathematica Symbol)

FresnelS[z] gives the Fresnel integral S(z).

KleinInvariantJ (Built-in Mathematica Symbol)

KleinInvariantJ[\[Tau]] gives the Klein invariant modular elliptic function J(\[Tau]).

Rationalize (Built-in Mathematica Symbol)

Rationalize[x] converts an approximate number x to a nearby rational with small denominator. Rationalize[x, dx] yields the rational number with smallest denominator that lies ...

SinIntegral (Built-in Mathematica Symbol)

SinIntegral[z] gives the sine integral function Si(z).

SolveAlways (Built-in Mathematica Symbol)

SolveAlways[eqns, vars] gives the values of parameters that make the equations eqns valid for all values of the variables vars.

WorkingPrecision (Built-in Mathematica Symbol)

WorkingPrecision is an option for various numerical operations that specifies how many digits of precision should be maintained in internal computations.

DirichletCharacter (Built-in Mathematica Symbol)

DirichletCharacter[k, j, n] gives the Dirichlet character \[Chi] {k, j} (n) with modulus k and index j.

Elliptic Integrals and Elliptic ... (Mathematica Tutorial)

Even more so than for other special functions, you need to be very careful about the arguments you give to elliptic integrals and elliptic functions. There are several ...

Line Search Methods (Mathematica Tutorial)

A method like "Newton's" method chooses a step, but the validity of that step only goes as far as the Newton quadratic model for the function really reflects the function. ...