264 
ME. W. H. L. EIJSSELL ON THE CALCULUS OF SYMBOLS. 
+ Ks) (?’2„-2(f ) . (s^) ?’2»-2(f)) 5 r^”'"+ &c. 
Hence equating coefficients of the powers of (§), 
92»-2(f) + 2W^f 0(§). . ^(f) = 2 ^)^2„_,(f) + ?>2„-2(f) + %)92n-l(?), 
whence 
<P2n-l{§)=nd(g), 
whence 
••■ (5r»+^(f).!r)”=!r»”+»«f .T*-' + . . ., 
the required expansion. 
