Problems of determining the temperature and density of heat sources from the initial and final temperatures

Under consideration are the three problems that simulate the process of determining the temperature and density of heat sources from some given initial and final temperatures. In the course of their mathematical formulation, some inverse problems arise for the heat transfer equation in which, together with the solution of the equation, one needs also to find the unknown right-hand side that depends only on the spatial variable. The existence and uniqueness theorems are proved for the solution.