| for a linear time-invariant system described by the second order differential equation|
the value of the coefficient ,
|t||is the time;|
|x||is a state variable of the system;|
|ω0||is the characteristic angular frequency of the system|
Note 1 to entry: When , is the eigen angular frequency of the system.
Note 2 to entry: This entry was numbered 351-24-18 in IEC 60050-351:2006.