  In this paper, we study the problem of finding the solution of a
multi-dimensional time fractional reactiondiffusion equation with nonlinear
source from the final value data. We prove that the present problem is not
well-posed. Then regularized problems are constructed using the truncated
expansion method (in the case of two-dimensional) and the quasi-boundary value
method (in the case of multi-dimensional). Finally, convergence rates of the
regularized solutions are given and investigated numerically.
