How to Determine Linear Dependence Using Wronskian: A Quick Guide

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The discussion focuses on using the Wronskian to determine linear dependence in differential equations. It clarifies that if the Wronskian is zero, the functions are linearly dependent, while a non-zero Wronskian indicates linear independence. Participants express confusion about needing to find solutions from initial values provided. It is confirmed that computing the Wronskian at a specific point, using the initial values, is sufficient to assess linear independence without needing to solve for the functions. The conversation concludes with the participant resolving their confusion regarding the use of initial values.
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urgent Diff. Eqs. Wronskian question

Homework Statement


See attached image- it's a lot easier.


Homework Equations


We know that when the wronskina = 0, it is linearly dependent on most points, and if it is not equal to 0, then the solutions form a fundamental set of solutions because they are linearly independent on all points.



The Attempt at a Solution



I am confused because it doesn't give solutions, just the initial values...do i have to go and FIND each solution (3) by order or reduction or something? Why did it give me those initial values?

Quick help is much appreciated.
 

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No, you don't have to compute the solutions. They gave you the initial values so you could compute the wronskian at x=0. That tells you something about linear independence. And you can also use them for the second part to figure which combination of y1, y2 and y3 will give you y. Write y(x)=a*y1(x)+b*y2(x)+c*y3(x). Figure out what a, b and c are.
 
Figured it out, thanks!
 
Question: A clock's minute hand has length 4 and its hour hand has length 3. What is the distance between the tips at the moment when it is increasing most rapidly?(Putnam Exam Question) Answer: Making assumption that both the hands moves at constant angular velocities, the answer is ## \sqrt{7} .## But don't you think this assumption is somewhat doubtful and wrong?

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