Cellulose Gel / Manufacturing. Microcrystalline cellulose (MCC) is derived from naturally occurring cellulose similar to that found in fruits and vegetables. From this natural source, FMC BioPolymer develops and customizes Avicel products, through various unique co-processing techniques.
The tangent plane at the point x=a, y=b is the plane that contains all the tangent vectors (at the point) of curves on the surface that pass through the point (a,b,f(a,b)). Another way to define it is to say that this is the plane through the point (a,b,f(a,b)) which is perpendicular to the NORMAL to the surface at that point. The NORMAL to the surface at a point is just defined as the direction perpendicular to all tangent vectors to the surface at that point. Therefore all we need to do to find the equation of the tangent plane is to find a normal to the surface at that point.
In the three-dimensional case a surface normal, or simply normal, to a surface at a point P is a vector that is perpendicular to the tangent plane to that surface at P. The word normal is also used as an adjective: a line normal to a plane, the normal component of a force, the normal vector, etc. That is, any vector orthogonal to all in-plane vectors is by definition a surface normal. If a (possibly non-flat) surface S is parameterized by a system of curvilinear coordinates x (s, t), with s and t real variables, then a normal is given by the cross product of the partial derivatives.