A solution of a matrix in classical option is found by means of Gauss's method. This method is based on a consecutive exception of unknown variables. The decision is carried out for an expanded matrix, that is with the included column of free members. At the same time the coefficients making a matrix as a result of the carried-out transformations form a step or triangular matrix. Rather main diagonal all coefficients of a matrix, except free members, have to be brought to zero.

All systems from three equations with three unknown are solved in one way – by consecutive replacement of the unknown with the expression comprising other two unknown, reducing thus their number.

Course of linear algebra and analytical geometry - basis of the higher technical education. ""Ruler"" comes to many students quite easily. Really, the main thing in linear algebra is to be able to solve the systems of the linear equations. The easiest way of calculation - Kramer's method.

The schedule of square function is called a parabola. This line has powerful physical value. On parabolas some celestial bodies move. The antenna in the form of a parabola focuses the beams going parallel to an axis of symmetry of a parabola. The bodies thrown up at an angle reach the top point and fall down, also describing a parabola. It is obvious that it is always useful to know coordinates of top of this movement.