Erect means build or upright. If you erect a house, you build it. If you stand erect, you hold your body as tall as possible.
A mathematical model is a description of a system using mathematical concepts and language.The process of building a mathematical model is termed mathematical modeling.Mathematical models are used in the natural sciences (such as physics, biology, earth science, meteorology) and engineering disciplines (e.g. computer science, artificial intelligence). mathematical model is a description of a system using mathematical concepts and language.
For the normal to 3D curves, see FrenetâSerret formulas. A polygon and two of its normal vectors. A normal to a surface at a point is the same as a normal to the tangent plane to that surface at that point. In geometry, a normal is an object such as a line or vector that is perpendicular to a given object.For example, in the two-dimensional case, the normal line to a curve at a given point is the line perpendicular to the tangent line to the curve at the point.n geometry, a normal is an object such as a line or vector that is perpendicular to a given object.