INVERSE

, is applied to a manner of working the rule of three, or proportion, which seems to go backward, i. e. reverse or contrary to the order of the common and direct rule: So that, whereas, in the direct rule, more requires more, or less requires less; in the Inverse rule, on the contrary, more requires less, or less requires more.

For instance, in the direct rule it is said, If 3 yards of cloth cost 20 shillings, how much will 6 yards cost? the answer is 40 shillings: where more yards require more money, and less yards require less money. But in the Inverse rule it is said, If 20 men perform a piece of work in 4 days, in how many days will 40 men perform as much? where the answer is 2 days; and here the more men require the less time, and the fewer men the more time.

Inverse Method of Fluxions, is the method of finding fluents, from the fluxions being given; and is fimilar to what the foreign mathematicians call the Calculus Integralis. See Fluents.

Inverse Method of Tangents, is the method of finding the curve belonging to a given tangent; as opposed to the direct method, or the finding the tangent to a given curve.

As, to find a curve whose subtangent is a third proportional to r - y and y, or whose subtangent is equal to the semiordinate, or whose subnormal is a constant quantity.——The solution of this problem depends chiefly on the Inverse method of fluxions. See TANGENT.

Inverse Proportion, or Inverse Ratio, is that in which more requires less, or less requires more. As for instance, in the case of light, or heat from a luminous object, the light received is less at a greater distance, and greater at a less distance; so that here more, as to distance, gives less, as to light, and less distance gives more light. This is usually expressed by the term Inversely, or Reciprocally; as in the case above, where the light is Inversely, or Reciprocally as the square of the distance; or in the Inverse or Reciprocal duplicate ratio of the distance.