Differentiation question with continuity

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The function f is continuous with continuous derivatives and satisfies the equation xf''(x) + f'(x) + xf(x) = 0, with the initial condition f(0) = 1. At x=0, it is determined that f'(0) = 0. To find f''(0), participants suggest differentiating the original equation and evaluating at x=0. This approach leads to further insights into the behavior of the function's derivatives. The discussion emphasizes the importance of applying differentiation to solve for higher-order derivatives.
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Homework Statement



Suppose a function f is continuous and has continuous derivatives of all orders for all
x. it satisfies xf ''(x) + f '(x) + xf(x) = 0. Given f(0) = 1

find the value of f '(0) and f '' (0).

Homework Equations


The Attempt at a Solution



when x=0,

0f''(0) + f ' (0) + 0f(0) = 0
therefore f ' (0) = 0

Now, I am not sure on how to find f ''(0). Is it undefined?
Thanks for your help.
 
Last edited:
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There's no attempt at a solution. You have to make one. Then you can get some help.
 
I have added the solution attempt, please help. Thanks :)
 
That helps. Try differentiating xf ''(x) + f '(x) + xf(x) = 0 and putting x=0 again.
 
Wow. Thanks Dick! :D
 
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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