Greg Harrington
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 Dec8 comment How to find the partial derivative of this function? Yes that is the reason. Thank you Dec8 comment How to find the partial derivative of this function? @pbs, the notation is saying the change in $\nu$ with $T$ while keeping $P$ constant. That is the notation my professor has given us and also how it is shown in the Thermodynamics book. I was just trying to be consistent Aug21 comment How to determine gradient of vector in cylindrical coordinates? @DoctorDan that resource is very helpful. I took multivariable calculus about 4 years ago and we are having a review in my graduate level fluid mechanics course and I am trying to remember all this stuff. Am I right in saying that the gradient of $\hat{V}$ in my original post is a vector and the divergence would be a scalar? Aug21 comment How to determine gradient of vector in cylindrical coordinates? I am working on a problem where I am trying to find the divergence of the vector in cylindrical coordinates but I need to find its gradient in order to do that. I have found the general form of the gradient online but I would like to understand how that was produced instead of copying it Aug21 comment How to determine gradient of vector in cylindrical coordinates? Yes that's what I meant. Sorry. The function I would be dealing with is still the one above Apr27 comment How do I find Laplace transform of $7t \cdot \mathrm{e}^{-3t}\cdot\sin(3t)$? This is perfect. Thank you very much Mar12 comment What function satisfies these conditions? I was dealing with a PDE for the non-homogeneous wave (string) equation which I believe was $u_{t}-u_{xx}=e^{t}$ and the first step in dealing with this type of problem was to find a function, $v(x,t)$ that satisfied the boundary conditions and the initial condition which were given to me. God I feel like an idiot not being able to to determine the function so I did all the other steps without it but not having it is probably gonna hurt me. I wish you guys were there helpin me today! Mar11 comment What function satisfies these conditions? I just took a partial differential equations exam and I had to find a function $v(x,t)$ to satisfy these two boundary conditions: $$u(0,t)=0$$ $$u(a,t)=0$$ and this initial condition: $u(x,0)=0$. I was stuck on this for most of the test and could not figure out $v(x,t)$ so I did the whole problem without it. What is it, it was driving me crazy Mar11 comment What function satisfies these conditions? I was able to do the rest of the problem. That was the first step of many. Thanks a lot! Mar11 comment What function satisfies these conditions? actually there was a third condition that i just saw and it was $u(x,0)=x$ so your function satisfies that as well. Thank you Mar11 comment What function satisfies these conditions? Is there anyway to determine this other than trial and error? Nov12 comment Did I use Laplace correctly? Thank you for the clarifying that I need to differentiate between t and s domains. Actually my homework involved finding the transfer function to this differential equation. I didn't think many on the math page knew about transfer functions but they could at least let me know if I was doing the Laplace correctly. Nov12 comment Did I use Laplace correctly? Yes I am sorry. This is the equation for an object's response to a step change in temperature. So $T_{a}$ is a constant as the ambient temperature and $\tau$ is the time constant. They are both just constants Jul19 comment How to solve a polynomial inequality? @Ross Millikan, thank you for the help but unfortunately graphing calculators are not allowed to be used in her class. If they were then she would have been able to find the answer and I would have not had to ask this question. I am just trying to teach her this stuff but the method that I said I was using wasn't taught to her yet. Jul19 comment How to solve a polynomial inequality? @The Chaz, Nobody is referring to themself in the third person. Like I said, this isn't for me. I'm an engineering student at Georgia Tech, and I haven't done things like this since 8th grade. All I asked was if there is another method of going about it since clearly her teacher put it on the test before teaching the method that I know of. As you can see, I know the most common method but it wasn't taught to her yet Jul19 comment How to solve a polynomial inequality? well the professor put it on a test ebfore they learned that material, so there must be another way