An important subset of optimization problems is constrained nonlinear optimization, where the function is not linear and the parameter values are constrained to certain ...

ArcTan[z] gives the arc tangent tan -1 (z) of the complex number z. ArcTan[x, y] gives the arc tangent of y/x, taking into account which quadrant the point (x, y) is in.

Information[symbol] prints information about a symbol.

InterpolatingFunction[domain, table] represents an approximate function whose values are found by interpolation.

Item[expr, options] represents an item within constructs such as Grid, Overlay, and Manipulate that displays with expr as the content, and with the specified options applied ...

MapAt[f, expr, n] applies f to the element at position n in expr. If n is negative, the position is counted from the end. MapAt[f, expr, {i, j, ...}] applies f to the part of ...

Mouseover[expr, over] represents an object that displays as over when the mouse pointer is over it, and as expr otherwise.

$MachineEpsilon gives the difference between 1.0 and the next-nearest number representable as a machine-precision number.

DSolve returns a general solution for a problem if no initial or boundary conditions are specified. The general solution to this equation is returned. However, if initial or ...

Matrix inversion. Here is a simple 2×2 matrix. This gives the inverse of m. In producing this formula, Mathematica implicitly assumes that the determinant ad-bc is nonzero.