The third of six volumes in Forsyth's Theory of Differential Equations series, concentrating on ordinary equations which are not linear.Originally published in 1900, this book constitutes the third of six volumes in Scottish mathematician Andrew Russell Forsyth's Theory of Differential Equations series, concentrating specifically on ordinary equations which are not linear. The text contains detailed information on the development of this area and substantial contributions made to it.Originally published in 1900, this book constitutes the third of six volumes in Scottish mathematician Andrew Russell Forsyth's Theory of Differential Equations series, concentrating specifically on ordinary equations which are not linear. The text contains detailed information on the development of this area and substantial contributions made to it.Andrew Russell Forsyth (18581942) was an influential Scottish mathematician notable for incorporating the advances of Continental mathematics within the British tradition. Originally published in 1900, this book constitutes the third of six volumes in Forsyth's Theory of Differential Equations series, concentrating specifically on ordinary equations which are not linear. The text contains detailed information on the development of this area and substantial contributions made to it. All sources are quoted in their proper connection and a few fresh investigations are added. Examples are given, where necessary, in order to provide illustrations of various methods. This book will be of value to anyone with an interest in differential equations and the history of mathematics.11. Reduced forms of systems of equations of the first order in the vicinity of singularities of the derivatives; 12. The integrals of the reduced forms of a system of equations, chiefly of two dependent variables; 13. Systems of equations with multiform values of the derivatives; singular solutions; 14. Equations of the second order and the first degree; 15. Equations of thel)