“…In the presence of unknown function .f .t/ ¤ 0/ and in contrast with the extensive literature on asymptotic stability and global nonexistence results for direct problems, there are few stability and blow-up results for hyperbolic and parabolic inverse problems (see [10][11][12][13][14]). In [11], Eden and Kalantarov considered the problem: u tt u juj p u C a.x, t, u, ru/ D f .t/!.x/, x 2 , t > 0, u.x, t/ D 0, x 2 , t > 0, u.x, 0/ D u 0 .x/, u t .x, 0/ D u 1…”