an CU 
mr 2 ; 
ie, (£) = sin & 
Bels 
and 2 C (cos 9)| is the coefficient of at in the development of 
SAM y=0 
—l(1—2acos?-+ e*) according to ascending powers of @, thus 1 for 
9 
n=0 and — cosn® for n> 0, we find the special relations: 
nr 
ea) 2r 
cos (t cos p cos wp) cos (t sin p sin w) 1 (t) dt r cos (2rp) cos (2rw) 
DP (A) 
r 
0 
co 2r 
fF (cos pcos W) cos (t sin p sin w) I(t) dt __ 
maa Saas meente de 
0 
(—1)r—1 4 = cos(2À +1) peos (LA + 1) w 
= Ss Ce ere oo. (2) 
co 2r +1 
ie (¢ cos p cos W) cos (1 sin p sin w) I (Dd 
Sear Re RE 
0 
(— 1) 4 *=2 € cos (2 À p) cos (2 Aw) 8 
= we deeemnnnnnnr nnn SEA 0 3 
oo 2r +1 
ee (tcosp cosw)cos (t sing sinw) I (dt _ 
; == 
0 
ay ae cos(2r+ 1) peos(2r +1) w 
ENTER! 4) 
From these your formulae arise immediately when we put 
Tt 
in (1) and (3). y= ni in (2) and (4) w=a and interchange 
; ; 4 y) 
moreover in the two last named p and @ i 
