Obtain the external force F(t)(t ≥ 0) given in the single-degree-of-freedom system above
Obtain the external force F(t)(t ≥ 0) given in the single-degree-of-freedom system above when the observed responses x(t) are
(1) e−αt (t ≥ 0) (4.91)
(2) αt · e−αt (t ≥ 0)
(3) e−(αt)2
(t ≥ 0)
(4) (αt)
2
e−(αt)2
(t ≥ 0).