Inverse

Part of speech: noun (n.)

That which is inverse. Thus the course of human study is the inverse of the course of things in nature. Tatham.

Part of speech: adjective (a.)

1. Opposite in order, relation, or effect; reversed; inverted; reciprocal; -- opposed to direct.

2. Inverted; having a position or mode of attachment the reverse of that which is usual.

3. Opposite in nature and effect; -- said with reference to any two operations, which, when both are performed in succession upon any quantity, reproduce that quantity; as, multiplication is the inverse operation to division. The symbol of an inverse operation is the symbol of the direct operation with -1 as an index. Thus sin-1 x means the arc whose sine is x. Inverse figures (Geom.), two figures, such that each point of either figure is inverse to a corresponding point in the order figure. -- Inverse points (Geom.), two points lying on a line drawn from the center of a fixed circle or sphere, and so related that the product of their distances from the center of the circle or sphere is equal to the square of the radius. -- Inverse, or Reciprocal, ratio (Math.), the ratio of the reciprocals of two quantities. -- Inverse, or Reciprocal, proportion, an equality between a direct ratio and a reciprocal ratio; thus, 4 : 2 : : , or 4 : 2 : : 3 : 6, inversely.