for $x=1$ function should be equal to $2$.
eq = E^-2 x Cos[Pi x] + c == 2; sol = Solve[eq /. x -> 1, c] (* {{c -> (1 + 2 E^2)/E^2}} *) %//N (* {{c -> 2.13534}} *) (eq /. x -> 1) /. sol (* {True} *)
Mariusz, I really really appreciate you and your help as always... very kind of you.
Thanks again.
