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In page Iterative method:

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Jamshīd al-Kāshī used iterative methods to calculate the sine of 1° and π in The Treatise of Chord and Sine to high precision. An early iterative method for solving a linear system appeared in a letter of Gauss to a student of his. He proposed solving a 4-by-4 system of equations by repeatedly solving the component in which the residual was the largest[citation needed].