138 MATHEMATICAL FORMULA AND ELLIPTIC FUNCTIONS 



6.806 /(*)=^* + &, 



= - x + b, o 



6.807 /(*)-*, 



. mrx 



Sm ' 



6.811 cos ax = sin air { h a / , , , cos wo; 



TT 1 2 a ^-^ w 2 - a 2 



= i 



6.812 sin a# = sin air ^ . 9 - w sin 

 TT ^^ w 2 a 2 



6. 



6.814 - 



= I 



sin nx 



n 



oo 



cos nx 



00 



7T 2 TTO: a: 2 ^^ cos nx 



~s 1 = / J V 



624 jLJ n 2 



n = i 



6.816 ^ - *T ^ ^ 



^^_^ / \ -I * I 



/ o-t/\ ^W^ v I/ 



6.810 # = 2 ^7^ sin wo; TT < # < TT 



n =i n tr 



-7T<*<7r 

 I O<#<27T I- 



2 2(1 cos #) <rf */ n 



O < tf < 27T 

 O < X < 27T 



6 4 12 *-J ir 



ri= i 



oo 



C 01 r, 7T 4 7T 2 ^ 2 7T^ 3 it 4 ^\ COS nX 



6.817 + - = > O < # < 27T 



90 12 12 48 ^^ W 4 



n = i 



CO 



* 010 TJ" # TT 2 ^ 3 7T^ 4 ^ "VT^ sin nx fo < x < 2?r 



b.818 ^ H ^ = 7 , ^> 



n = i 



90 36 48 240 ^M/ W 5 



