There is no one specific person who invented the polynomials, but their history can be traced back to the Babylonians. They used verbal instructions for solving problems related to quadratics.
Scipione del Ferro solved cubic equations, but he did not publish his solutions. Girolamo Cardan published "Ars Magna" or "The Great Art." This book contained details of quartic and cubic study, considered as modern algebra's beginning. Both Sir Isaac Newton and Rene Descartes also contributed in terms of polynomials' roots. In 1669, Newton established an iterative method for numerical estimation of polynomial roots. Newton's parallelogram was created in 1676 for estimating all possible "y" values that are related to "x." The resolution and invention of polynomials continued with Carl Gauss, Evariste Galois and many more over the years.