Omar Khayyam cubic equation
- Gary Rubinstein
This is Omar Khayyam's construction for cubic equations of the form x^3+bx^2+cx=d. The circle's diameter has endpoints (-b,0) and (d/c,0). The hyperbola has a horizontal asymptote at y=-sqrt(c) and passes through the point (d/c,0). The x coordinate of the other intersection point is one of the solutions to the cubic equation.