The ninth homework set is due at the start of class on Monday 02/11/02 and consists of the following problems:

23, 24, 25, 26, 40 and 41. From the problems at the end of Chapter 4 of Notes for a First Course in Electrical Systems.

Selected answers are:

23.	Eigenvalues are:  -6125.7 and -27207.6
24.	i(t)  = -1.304.exp(-1833t)sin(12779t) mA
25.	Vc(t) = -133.3.t.exp(-10000t) kV
26.	Vc(t) = -13.4.exp(-1000t)sin(9950t) V
	Wc(0) =0,	Wl(0) = 0.444 mJ
40.	Vr(t) = 0.2665.cos(25t) + 0.00355.sin(25t) - 0.2665exp(-1875t)  V
41.	V(t) = -10.8exp(-312.5t).cos(1740t) + 4.18exp(-312.5t).sin(1740t) + 0.821.cos(1257t) - 1.62.sin(1257t) V