General Case
Consider a system of n linear equations for n unknowns, represented in matrix multiplication form as follows:
|
|
where the n by n matrix has a nonzero determinant, and the vector is the column vector of the variables.
Then the theorem states that in this case the system has a unique solution, whose individual values for the unknowns are given by:
where is the matrix formed by replacing the ith column of by the column vector .
The rule holds for systems of equations with coefficients and unknowns in any field, not just in the real numbers. It has recently been shown that Cramer's rule can be implemented in O(n3) time, which is comparable to more common methods of solving systems of linear equations, such as Gaussian elimination.
Read more about this topic: Cramer's Rule
Famous quotes containing the words general and/or case:
“The general Mistake among us in the Educating of our Children, is, That in our Daughters we take Care of their Persons and neglect their Minds; in our Sons, we are so intent upon adorning their Minds, that we wholly neglect their Bodies.”
—Richard Steele (1672–1729)
“In the case of pirates, say, I would like to know whether that profession of theirs has any peculiar glory about it. It sometimes ends in uncommon elevation, indeed; but only at the gallows.”
—Herman Melville (1819–1891)