FlatGraph Version 1 descriptions Plotting functions with more possibilities. Differentiation of any order . Construction of tangents to the graph. The simple & clear interface with the detailed documentation & examples of work. The program is designed both for inexperienced & the professional user as in it are combined the intuitive interface & professional functions. FlatGraph allows: - To enter one or several functional expressions of any complexity for display & their differentiation - To carry out symbolical differentiation for the specified order of a derivative & also to carry out simplification of the received derivative - To investigate "alive" changing of various parameters of functions with simultaneous display of new graphs that allows to define influence of parameters of functions on their form - To use automatic or manual scaling schedules of functions for linear scales - To display parametric functions for example ellisoid cardioid Bernoulli lemniscate & other similar graphs - To solve the equations system of the equations & inequalities by graphic way - To define & display a tangent to the graph of function in a point x0 . FlatGraph has the simple & clear interface detailed user guide & examples of work.