The fundamental theorem of algebra before Carl Friedrich Gauss.
This is a paper about the first attemps of demonstration of the fundamental theorem of algebra. Before, we analyze the tie between complex numbers and the number of roots of an equation of n-th degree. In the second paragraph, we see the relation between integration and the fundamental theorem. Finally, we observe the linear differential equation with constant coefficients and Euler's position about the fundamental theorem, and then we consider d'Alembert's, Euler's...