DIFFERENTIAL EQUATIONS 205 



9.216 Ker and Kei Functions: 



ker x + i kei x = K (xVi), 

 ker x - i kei x = K (ixVi), 



9.220 The Bessel-Clifford Differential -Equation: 



With the substitution: 



z 



the differential equation reduces to Bessel's equation. 

 9.221 Two independent solutions of 9.220 are: 



k = 



9.222 



9.223 If v = n, an integer: 



9.224 Changing the sign of v, the corresponding solution of: 



y = x v C v (x}. 



