Can the vectors (left[begin{array}{lll}1 & 2 & 2.5end{array} ight]^{T}) and (left[begin{array}{lll}1 & 2 & -2end{array} ight]^{T}) be mode shape vectors of a system with a

Can the vectors \(\left[\begin{array}{lll}1 & 2 & 2.5\end{array}\right]^{T}\) and \(\left[\begin{array}{lll}1 & 2 & -2\end{array}\right]^{T}\) be mode shape vectors of a system with a diagonal mass matrix with all three diagonal elements equal?