DE QUATRE FONCTIONS. \1 



Si, on remplace les puissances des cosinus en fonction des cosinus des arcs multiples, il vient : 



(HI). 

 19 ( *~~3 X I ! ([2, 



sin. x 2 ) 2*"-' 0'" + ' 



] [2+2,u-Hl[2iH-2,l] [2u-t-4, u+2] [2u+4, 2] [2u-t-6, M-4-5] [2+6, o] 



,S] [3'H-a, 1] [2u-f-2,4] [2iM-t,21[2tM-4,a] J2u+6, 5] [2+6, 6] 



+ 3 



,3] [3<H-4, 2] [2.M-4, 4] [2iM-6,3] [2M-6, S] 



" + 7 



[2u-t-2, 1 ] [21H-2, 21 ^_ [2tH-*, 2] [2u-V-t, 3] [2iH-6, 3] [2iH-6, 4] 

 ~2 7 ^ 



cos . (2u _ 2 . 



i[2u,0] [2u+2, 1] [2u+2, I] [2tH-4,2][2u_4-4,2] [2w+6, 3] [2ii+6, 3] 



[2u+2,l][2tt+2,0] [2M+4,2][2u-4-4,l] [2u+6,5] [2iH-6,3] 



[2u+4,2][2u+4,0] [2u-4-6,5][2+6,l] 



rf . cos . 

 I 



[2u-(-6,3][2m-6,0] 



Etc. 



TOME XXI. 



