Frobenius series

#math
Let us consider the equation (1) again, and say the expansion $$\begin{align} xP(x) &= p_{0} + p_{1}x + p_{2}x^2 \dots \ x^2Q(x) &= q_{0} + q_{1}x + q_{2}x^2 \dots \end{align}$$are valid in |x|<R;R>0.
Let the indicial equation $$r(r-1) + p_{0}r + q_{0} = 0$$have real roots m1 and m2 (with m2m1). Then the DE is guaranteed atleast one solution $$y_{1} = x^{m_{1}}\sum_{m=0}^\infty a_{m}x^m; a_{0} \neq 0$$
The other solution is determined as follows :

  1. If m1m2 is neither 0 nor an integer, then in this case other solution $$y_{2} = x^{m_{2}} \sum_{m=0}^\infty a_{m}x^m; a_{0} \neq 0$$
  2. If m1=m2, then in this case $$y_{2} = y_{1}\ln x + x^{m_{2}}\sum_{m=0}^\infty A_{m}x^m\ ;\ a_{0} \neq 0$$
  3. If m1m2 is an integer, then other solution $$y_{2} = ky_{1}\ln x + x^{m_{2}}\sum_{m=0}^\infty A_{m}x^m\ ;\ a_{0} \neq 0$$k may be zero.

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