the natural frequencies of the below 3 DOF systemfundamental natural frequency of spring mass system using dunkerley's methodfirst influence coefficient for mass 2m are given as?11=(1/3k); ?22=?33=(1/3k second influence coefficients for mass 2m are given as?22=((1/3k)+(1/2k))=((2+3)/(6k)) =(k/6k) ?21=(1/3k)