线性代数复习知识（Review knowledge of linear algebra）.docVIP

线性代数复习知识（Review knowledge of linear algebra） Linear algebra knowledge point framework (1) The starting point of Linear Algebra Learning: linear equations. In other words, linear algebra can be seen as a discipline established in the study of the object of linear equations. The characteristics of linear equations are: the equation is a homogeneous formula of the unknowns, the number of equations, the number of S and the number of unknowns, n can be the same, or different. About the solution of linear equations, there are three issues worthy of discussion: (1) equations is solvable, namely the existence problem of the solution; (2), how to solve the equations, the number of solutions; (3) equations, there is more than one solution, these solutions are different no internal relations, namely the structure of solutions of problems. Gauss elimination method, the basis and method for solving linear equations directly, which involves three kinds of equation of the same solution transform: (1), the K times to an equation, another equation; (2), a two exchange equation (3), location; with a constant number multiplied by a K equation. We refer to these three transformations as elementary transformations of linear equations. Any system of linear equations can be transformed into ladder equations by elementary transformation. As can be seen from the concrete example, after being reduced to a ladder equation set, the value of each unknown can be solved in turn, thus the solution of the system of equations is obtained. The equations play a decisive role is unknown coefficient and relative position, so we can put all the coefficients and constants in terms of the original position of the extracted equations, the formation of a table, through the study of this table, we can determine the solution. We call such a table consisting of several numbers in a certain way called a matrix. A linear system of equations can be expressed in terms of matrices, which are at least more concise in