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If two (or more) unknown quantities enter an equation, for every value of the one there will be generally a corresponding value of the other; such an equation, not serving to determine either, is an Indeterminate equation. A problem whose algebraical statement gives rise to such an equation is an I. problem. It may happen that the solutions of such an equation may be limited by a condition, e.g. that only positive integral values of the unknown quantities are admissible; the rules for finding such values, if any, are the subject of I. analysis. The method of I. coefficients consists in assuming the form of the expansion of a function, and using the assumption as a means of finding the value of the terms successively.