756 
PONTIFICIAE ACADEMIAE SCIENTIARVM SCRIPTA VARIA - 28 
Approximate Expressions for the Principal Magnitudes 
126. For small values of 7’ it is possible to write from (122-1) 
and (123-5) 
(126- 
D R()=R,(0) [rive 20” 
/ —— +...) (0)d 8 
œæ 70, 17°8% 
(x26-2) C(t)=R,,(t)[ _ Tt q(ojde 
9 
thus we have from (112-1) 
(126-3) 
(126-4) 
R, (£) + Ro (6) [r+ÿ ©] 
| C(t) ~ OR, (¥) 
and according to (110-2) 
(126-5) 
R(t) ~R, (t) [1+i 0] 
whence 
(126-6) 
(126-4) 
Ym oN © 
R. 
a) 
2 
ignoring first order terms containing 7 and :. 
"111 Allais - nag. 60