Chebyshev approximation of the steel magnetization characteristic by the sum of a linear expression and an arctangent function

The properties of a Chebyshev approximation by the sum of a linear expression and an arctangent function have been investigated.  The condition has been established under which a Chebyshev approximation by this expression with the smallest absolute error and with the reproduction of the function value at the leftmost point exists and is unique.  A method of determining the parameters of this approximation has been suggested and substantiated.  The results of a Chebyshev approximation of the magnetization characteristic of electrotechnical steel by the sum of a linear expression and an arctangent function have been presented.

Chebyshev (uniform) approximation with condition
Chebyshev аlternance рoints
magnetization characteristic of steel
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