types:
expansion
a function expressed as a sum or product of terms
inverse function
a function obtained by expressing the dependent variable of one function as the independent variable of another; f and g are inverse functions if f(x)=y and g(y)=x
Kronecker delta
a function of two variables i and j that equals 1 when i=j and equals 0 otherwise
metric,
metric function
a function of a topological space that gives, for any two points in the space, a value equal to the distance between them
transformation
(mathematics) a function that changes the position or direction of the axes of a coordinate system
isometry
a one-to-one mapping of one metric space into another metric space that preserves the distances between each pair of points
operator
(mathematics) a symbol or function representing a mathematical operation
threshold function
a function that takes the value 1 if a specified function of the arguments exceeds a given threshold and 0 otherwise
series
(mathematics) the sum of a finite or infinite sequence of expressions
reflection
(mathematics) a transformation in which the direction of one axis is reversed
rotation
(mathematics) a transformation in which the coordinate axes are rotated by a fixed angle about the origin
translation
(mathematics) a transformation in which the origin of the coordinate system is moved to another position but the direction of each axis remains the same
affine transformation
(mathematics) a transformation that is a combination of single transformations such as translation or rotation or reflection on an axis
linear operator
an operator that obeys the distributive law: A(f+g) = Af + Ag (where f and g are functions)
sin,
sine
ratio of the length of the side opposite the given angle to the length of the hypotenuse of a right-angled triangle
cos,
cosine
ratio of the adjacent side to the hypotenuse of a right-angled triangle
tan,
tangent
ratio of the opposite to the adjacent side of a right-angled triangle
cotan,
cotangent
ratio of the adjacent to the opposite side of a right-angled triangle
sec,
secant
ratio of the hypotenuse to the adjacent side of a right-angled triangle
cosec,
cosecant
ratio of the hypotenuse to the opposite side of a right-angled triangle
dilation
(mathematics) a transformation that changes the size of a figure but not its shape