Electronic Journal of Differential Equations, Vol. 2010(2010), No. 161, pp. 1-25. Title: Analysis of a quadratic system obtained from a scalar third order differential equation Authors: Fabio Scalco Dias (Univ. Federal de Itajuba, Brazil) Luis Fernando Mello (Univ. Federal de Itajuba, Brazil) Abstract: In this article, we study the nonlinear dynamics of a quadratic system in the three dimensional space which can be obtained from a scalar third order differential equation. More precisely, we study the stability and bifurcations which occur in a parameter dependent quadratic system in the three dimensional space. We present an analytical study of codimension one, two and three Hopf bifurcations, generic Bogdanov-Takens and fold-Hopf bifurcations. Submitted February 15, 2010. Published November 10, 2010. Math Subject Classifications: 70K50, 70K20, 34C60. Key Words: Bifurcation; Hopf bifurcation; Bogdanov-Takens bifurcation; fold-Hopf bifurcation; limit cycle; stability; quadratic system.