S: (n) expansion (a function expressed as a sum or product of terms) "the expansion of (a+b)^2 is a^2 + 2ab + b^2"
S: (n) 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)
S: (n) Kronecker delta (a function of two variables i and j that equals 1 when i=j and equals 0 otherwise)
S: (n) metric function, metric (a function of a topological space that gives, for any two points in the space, a value equal to the distance between them)
S: (n) transformation ((mathematics) a function that changes the position or direction of the axes of a coordinate system)
S: (n) isometry (a one-to-one mapping of one metric space into another metric space that preserves the distances between each pair of points) "the isometries of the cube"
S: (n) operator ((mathematics) a symbol or function representing a mathematical operation)