For 10 points, name these rectangular arrays of numbers encountered in mathematics.
The Jacobian type of these structures is often used when changing between coordinate systems while the Hessian variety is used in analyzing the critical point of a multivariable function. Eigenvalues can be found by solving the characteristic polynomial of square ones, which sets their determinant equal to zero. Two of them can be multiplied if the number of columns in the first one equals the number of rows in the second. For 10 points, name these rectangular arrays of numbers encountered in mathematics.
The Jacobian type of these structures is often used when changing between coordinate systems while the Hessian variety is used in analyzing the critical point of a multivariable function.
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