VectorAngle[u, v] gives the angle between the vectors u and v.

Sign[x] gives -1, 0, or 1 depending on whether x is negative, zero, or positive.

PointSize[d] is a graphics directive which specifies that points which follow are to be shown if possible as circular regions with diameter d. The diameter d is given as a ...

PerformanceGoal is an option for plotting and various other algorithmic functions that specifies what aspect of performance to try to optimize with Automatic settings for ...

JacobiSymbol[n, m] gives the Jacobi symbol (n/m).

Thickness[r] is a graphics directive which specifies that lines which follow are to be drawn with thickness r. The thickness r is given as a fraction of the horizontal plot ...

Likelihood[dist, {x_1, x_2, ...}] gives the likelihood function for observations x_1, x_2, ... from the distribution dist.

Placeholder[name] represents a placeholder labeled with name that indicates a place to type.Placeholder[] gives the empty placeholder \[Placeholder].

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 ...

The solutions to many second-order ODEs can be expressed in terms of special functions. Solutions to certain higher-order ODEs can also be expressed using AiryAi, BesselJ, ...