Identifying and Classifying Singular Points in Differential Equations

Ted123
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Homework Statement



Locate the singular points of x^3(x-1)y'' - 2(x-1)y' + 3xy =0 and decide which, if any, are regular.

The Attempt at a Solution



In standard form the DE is y'' - \frac{2}{x^3} y' + \frac{3}{x^2(x-1)} y = 0.

Are the singular points x=0,\pm 1\;?

Regular singular points x_0 of y'' + p(x)y' + q(x)y =0 satisfy (x-x_0)p(x) ,\; (x-x_0)^2q(x) both finite as x \to x_0.

Considering x \left( -\frac{2}{x^3} \right),\; (x-1) \left( -\frac{2}{x^3} \right) ,\; (x+1) \left( -\frac{2}{x^3} \right) none of which are finite as x\to x_0 Does this mean there are no regular singular points?
 
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Ted123 said:

Homework Statement



Locate the singular points of x^3(x-1)y'' - 2(x-1)y' + 3xy =0 and decide which, if any, are regular.

The Attempt at a Solution



In standard form the DE is y'' - \frac{2}{x^3} y' + \frac{3}{x^2(x-1)} y = 0.

Are the singular points x=0,\pm 1\;?

Regular singular points x_0 of y'' + p(x)y' + q(x)y =0 satisfy (x-x_0)p(x) ,\; (x-x_0)^2q(x) both finite as x \to x_0.

Considering x \left( -\frac{2}{x^3} \right),\; (x-1) \left( -\frac{2}{x^3} \right) ,\; (x+1) \left( -\frac{2}{x^3} \right) none of which are finite as x\to x_0 Does this mean there are no regular singular points?
What's wrong with (x- 1)\left(\frac{2}{x^3}\right) as x goes to 1?
 
HallsofIvy said:
What's wrong with (x- 1)\left(\frac{2}{x^3}\right) as x goes to 1?

Doh - I've tended to 0 on every limit! :rolleyes:
 
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