Need help interpreting the Wronskian

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SUMMARY

The discussion centers on the interpretation of the Wronskian for the functions {x, xe^x, x^2e^x}. The calculated Wronskian is W(x) = x^3e^x, which equals zero at x = 0. However, it is established that the functions remain linearly independent on any interval that does not include the point x = 0. This confirms that the presence of a zero Wronskian at a single point does not imply linear dependence across the entire interval.

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kostoglotov
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I'm given bases for a solution space \left \{ x,xe^x,x^2e^x \right \}. Clearly these form a basis (are linearly independent).

But, unless I've made a mistake, doing the Wronskian on this yields W(x) = x^3e^x.

Isn't this Wronskian equal to zero at x = 0? Isn't that a problem for dependence/independence?

note: a DE to which this solution space applies has not been provided in the exercise.
 
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kostoglotov said:
I'm given bases for a solution space \left \{ x,xe^x,x^2e^x \right \}. Clearly these form a basis (are linearly independent).

But, unless I've made a mistake, doing the Wronskian on this yields W(x) = x^3e^x.

Isn't this Wronskian equal to zero at x = 0? Isn't that a problem for dependence/independence?
No. The three functions are linearly independent on any interval that doesn't include 0. I'm assuming that you correctly evaluated the Wronskian.
 

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