Surfaces in three-dimensional space can be represented through explicit, parametric and implicit equations, which describe the relationship between the variables x, y and z. Graphs of linear equations produce flat planes, while quadratic equations form objects such as spheres or ellipsoids. In this research, a theoretical approach is combined with interactive visualization to analyze various surface shapes. Through the use of GeoGebra software, this analysis makes it easier to understand surface orientation and shape, such as normal vectors and curvature, as well as applications in vector fields. This research also investigates the concepts of Cartesian coordinates in three-dimensional space, by depicting surfaces in the form of graphs of functions of two variables. It is hoped that the results of this research can provide deeper insight into the geometric properties of surfaces and how to visualize them effectively in mathematics and physics applications.

This study aims to solve the population dynamics model using the Euler method, where the model is a nonlinear differential equation. The research methods used are literature study and simulation methods. In theory, the Euler Method is a numerical method that is often used in solving initial value problems. The Euler method is obtained by decomposing a function into a Taylor series up to two initial terms. This method has an accuracy of one.