Semi special contact 2-geodesic transformations of AC-structures

In this paper we investigate the properties of semi-technical contactly 2-geodesic transformations of the almost contact metric structure (AC-structures), which was introduced in [1]. In the first part of the work we found invariant form of structural tensors (see [2].) of almost contact metric structures, which has been used to find the transformation formulas of structural tensors of almost contact metric structures when a contactly 2-geodesic transformations. Next we obtained invariant almost contact metric structures when contactly 2-geodesic transformations of the first linear type. So-called a semi-technical a contactly 2-geodesic transformations were allocated, and formulas for the transformation of structural tensor were obtained when a semi-technical 2-geodesic transformations. Finally, we obtain the identity, which affinor of semi-technical 2-geodesic transformations satisfies.