916 
applying the following trigonometric relations: 
AAAS ese Goes tanseee lee a 
ro sin x l~ tan® x 
and combining with Eqe (I-22) 
tan oki = wo 
2 
200 ee) 
t SS Se S os eternal - 
an ot, SES aeiael: ty = tan ary geuee (I-23 ) 
Combining Eqse (I-21) and (I-22): 
F 1 ~ w% 9% F 200 
xe=/1 EIS 
k 14k gh | ~ moe) Te ge 
2 92 
ANS 0 Ca aa 2 
eee ar gn!) Oy wi toast. oF 
2F tm 
x2 a [ - 20 | (I-24) 
The response (relative to step response): 
th 
21-2 I-25 
s = ( ) 
It should be noted that an additional consideration arises in cases of low 9 
where @ becomes < t,- If the driving function actually continues to go 
negative for t = 0, the above development is applicable. If, however, the 
driving function remains zero for t > @, it would be necessary to solve 
Eqe (I-5) with 
-101= 
