Cardano and the cubic

Frank Sottile

  You all know the quadratic formula for the solutions to a quadratic
equation.  What you may not know is that there is a formula for the
solutions to a cubic equation (and also for a quartic equation), due 
to the Italian mathematicans Tartaglia, Cardano, and Ferraro.  In this 
activity we will work to solve the cubic equation and discuss formulas 
for solutions to equations.