#NEWLINE# def fdiff( self , argindex = 1 ) : #NEWLINE# #INDENT# x = self . args [ 0 ] #NEWLINE# if ( argindex == 1 ) : #NEWLINE# #INDENT# return ( ( ( x * cos ( argindex ) ) - sin ( x ) ) / ( x ** 2 ) ) #NEWLINE# #UNINDENT# else : #NEWLINE# #INDENT# raise ArgumentIndexError ( self , argindex )