KO pt 
= Fes sinh (0, \K- -—1 7) (6.67) 
KO pt i / 9 / 2 
G(t) = (<. a a (6.68) 
nvVKo— 
er@nt \ 
=—=> sin (0, Wiape 7) (6.68°) 
This equation is in the form of the impulse response function when x < 1, as in 
Fig. 6.5. 
c. When x = 0, G(t) shows an undamped sine curve as is also shown in Fig. 6.5. 
G(t) 
t exent 
K<1 
0 
—_—> | 
Git 
t xr=0 
0 
— > { 
Fig. 6.5. G(t)forx<1,x=0. 
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