Cubic polynomial roots using symbolic solutions

Move the points [color=#9900ff][b]P1[/b][/color], [color=#9900ff][b]P2[/b][/color], [color=#9900ff][b]P3[/b][/color], [color=#9900ff][b]P4[/b][/color] to get a new cubic polynomial and find its roots.

Information: Cubic polynomial roots using symbolic solutions