1. There are conventional methods for finding multiple roots of equations, such as the Muller method and Bairstow method. The Muller method uses three initial values to obtain the coefficients of a parabola, which are then substituted into the quadratic formula to estimate the root where the parabola intersects the x-axis. The Bairstow method iteratively calculates the factors of a polynomial to determine its roots.
2. Complex roots of equations can be calculated using Euler's formula, which states that every complex number has exactly n complex roots. The formula generates each root by substituting different values for k between 0 and n-1. This allows polar forms of complex numbers to be substituted to find their roots