Solving non-homogeneous PDE (unsure of methodology)

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Homework Statement



u_{t} = ku_{xx}
u_{x}(0, t) = 0
u_{x}(L, t) = B =/= 0
u(x, 0) = f(x)


Homework Equations





The Attempt at a Solution



I believe that no equilibrium solution exists because we can't solve
u_{xx} = 0
with our boundary conditions. I'm a little lost as to where to take this question from here.

Been trying to work with this question for around 30 minutes now, I'm lost. :D
 
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Think I figured it out now, derp...

I just chose a reference function
r(x, t) = r(x) = c_{1}\frac{x^2}{2}
and solved for c1 which allowed me to generate a new linear homogeneous PDE and summed up the solution and the reference function to find the final solution. Would be nice if someone replied that I used the correct method though! Thanks!
 
Yes. Find a function that satisfies the boundary conditions with regard to the differential equation, then subtract it off to get a new differential equation with homogeneous boundary conditions.
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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