The following paper is available at the address given below Some differential equations in Synthetic Differential Geometry by Anders Kock and Gonzalo E. Reyes Abstract: Some differential equations are considered in the context of Synthetic Differential Geometry. Here, this means that not only nilpotent infinitesimals, but also the formation of function spaces is exploited. In particular, we utilize distribution spaces in our study of wave and heat equations. Address: http://xxx.lanl.gov/list/math.CT/recent#2