What Determines Regular and Irregular Singular Points in Differential Equations?

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Rijad Hadzic
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Homework Statement


Determine singular points of given DE. Classify as regular or irregular

[itex](x^3 -2x^2 + 3x)^2 y'' + x(x-3)^2 y' + (-x-1)y = 0[/itex]

Homework Equations

The Attempt at a Solution



From the polynomial infront of y'' I get

[itex]x^2 (x^2 -2x + 3)^2[/itex]

right out of the bat I can see that x = 0 is going to be a regular point.

the zeros of [itex]x^2 -2x +3 = 1\frac +- \frac {8^{1/2}}{2}[/itex]

so since the denominator of y' will have [itex]x^2 -2x +3 = 1\frac +- \frac {8^{1/2}}{2}[/itex] to the second power, can I say that [itex]x^2 -2x +3 = 1\frac +- \frac {8^{1/2}}{2}[/itex] are the irregular points then?
 
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Rijad Hadzic said:

Homework Statement


Determine singular points of given DE. Classify as regular or irregular

[itex](x^3 -2x^2 + 3x)^2 y'' + x(x-3)^2 y' + (-x-1)y = 0[/itex]

Homework Equations

The Attempt at a Solution



From the polynomial infront of y'' I get

[itex]x^2 (x^2 -2x + 3)^2[/itex]

right out of the bat I can see that x = 0 is going to be a regular point.

the zeros of [itex]x^2 -2x +3 = 1\frac +- \frac {8^{1/2}}{2}[/itex]

so since the denominator of y' will have [itex]x^2 -2x +3 = 1\frac +- \frac {8^{1/2}}{2}[/itex] to the second power, can I say that [itex]x^2 -2x +3 = 1\frac +- \frac {8^{1/2}}{2}[/itex] are the irregular points then?
It is not correct to say ##x^2 -2x +3 = 1 \pm\frac {8^{1/2}}{2}##. I think what you mean is ##x^2 -2x +3 = (x-1 + \frac {8^{1/2}}{2})(x-1 - \frac {8^{1/2}}{2})##. That is still not right, though, because you have made a mistake in solving for the roots of ##x^2-2x+3##.