INFINITE SERIES 123 



6.43 



i. log sin x = log x - ^ x 2 + -i- # 4 + ^ x 6 + . 



I5O 2835 



S*~~ 2 2n ~ 1 

 j 



2. log COS * = -- 2 -- X 4 -- jf 



2 12 45 2520 



. x 



* 



(2)! . 4 



4. log cos # = | sin 2 x + - sin 4 + - sin 6 x + . . . 



6.44 



i. log (i + ^) = x - x 2 + - x s 



{log (I + X)}P see 7.369. 



2*-*! (-!)! (2..+ 



r 



I) 



