A differential-algebraic equation (DAE) is a type of differential equation in which the derivatives are not (in general) expressed explicitly, and typically derivatives of some of the dependent variables may not appear in the equations at all. The general form of a system of DAEs is given by

where .
Differential-algebraic equations can be solved numerically in the Wolfram
Language using the command NDSolve,
and some can be solved exactly with DSolve.

A system of DAEs can be converted to a system of ordinary differential equations by differentiating it with respect to the independent variable .

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