Graphical slide rule for solving equations - has cursors inter ecting curves determining roots of cubic and quadratic equations

摘要

The fixed rule is marked with a set of hyperbolas. It has a frame moving along its longest side, carrying two cursors, one marked with a parabola, the other with the Y-axis. The cursors can thus move along both the X and Y axis of the fixed rule. The parabola is used against fixed axes to solve quadratic equations. Cubic equations are first divided by Ax to convert them into a combination of a hyperbola and a quadratic whose x2 coefficient is unity. Both parabola and hyperbola are then used to obtain the roots.