5. Linear operators in plane analytic geometry.

If we interpret a two-dimensional vector v(xv;yv) as a point V(xv;yv) in the cartesian plane Oxy, the linear invertible operators represented by square 2x2 matrices act as bijective transformations of the point V(xv;yv) into a point V'(xv';yv') of Oxy. We shall call these transformations geometric linear transformations.

Such transformations show interesting geometric properties.