Since you have'nt replied i presume you have'nt got the answer:
Consider a two span continuous beam of spans L1, L2 respectively, this has three supports all pinned.Say both spans have a udl of x KN/m. Now assume rotation of support 1(left extreme) is say "Y", rotation to the left of...
When you say compatibility it is meant compatibility of displacements not forces so your question "Can u give one such example for displacement method too(that is where a no. of sets of forces satisy compatibility but only one realistic se satisfies equilbrium" is wrong instead it...