Nature
Solution of Cubic and Biquadratic Equations - Nature
...Proceedings of the Edinburgh Mathematical Society (April 7, 1890), where it is shown that, with the exception of the case where the roots of the biquadratic are equal in pairs, the real roots of the general biquadratic can be found graphically by means of two equal parabolas having their axes at right angles, the one fixed and the other movable; and also that every cubic can be reduced to the form y3 ± y + r = 0; and then solved graphically by means of the fixed curve y = x3 and the movable straight line x±y = r.
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