# Veryfing ODE for complicated y(t)

by rdioface
Tags: complicated, veryfing
 P: 11 1. The problem statement, all variables and given/known data For the differential equation, verify (by differentiation and substitution) that the given function y(t) is a solution. 2. Relevant equations $y' - 4ty = 1$ $y(t) = \int_{0}^{t} e^{-2(s^{2}-t^{2})} ds$ 3. The attempt at a solution I attempted to take $\frac{d}{dt}$ of y(t) as usual but 1. if I do not try bringing the $\frac{d}{dt}$ inside the integral I can do nothing because there is no elementary antiderivative of y(t). 2. if I do bring the $\frac{d}{dt}$ inside the integral, I can use the chain rule to get $y(t) = (-2) \int_{0}^{t} (-2t) e^{-2(s^{2}-t^{2})} ds$ but since my variable of integration is ds not dt, this doesn't allow me to use a u-substitution as I had hoped nor can I think of a way to relate ds and dt. More or less I do not know how to take $\frac{d}{dt}$ of y(t) and I do not know any other ways to solve the problem.
 P: 43 Do you have to do it that way? Because it looks like you can solve it linearly.
 P: 11 Yes, the problem asks to verify that y(t) is a solution to the differential equation y' + 4ty = 1.
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P: 25,235
Veryfing ODE for complicated y(t)

 Quote by rdioface $(-2) \int_{0}^{t} (-2t) e^{-2(s^{2}-t^{2})} ds$ but since my variable of integration is ds not dt, this doesn't allow me to use a u-substitution as I had hoped nor can I think of a way to relate ds and dt.
I don't think you have to be able to do the integral to identify that expression as $4 t y(t)$. Since you are integrating ds you can factor out the t.
P: 11
 Quote by Dick I don't think you have to be able to do the integral to identify that expression as $4 t y(t)$. Since you are integrating ds you can factor out the t.
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Thanks!

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