The Arsacid Dynasty ruled Parthia, which included the Iranian plateau and intermittently Mesopotamia, from 253 BC until their overthrow by the Sassanid Dynasty in AD 224. The members of this dynasty include:
... quadratic formula expresses the explicit solution(s) x to the quadratic equation
<math>ax^2+bx+c=0</math>
in terms of the coefficients a, b and c, ...