How do you solve for multiple constants given the wave functions at the boundary?

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To solve for multiple constants given wave functions at a boundary, equate the wave functions ψ1(x) and ψ2(x) at x = a, resulting in ψ1(a) = 0 and ψ2(a) = (a-d)² - c. The discussion emphasizes the importance of ensuring continuity not only of the wave functions but also of their first derivatives at the boundary. Clarification was provided that equating the wave functions at the boundary is necessary for solving the problem. The conversation concludes with acknowledgment of the assistance received in understanding the process.
Danielk010
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Homework Statement
In the region 0 ≤ x ≤ a, a particle is described by
the wave function ψ1(x) = ##−b(x^2 − a^2 )##. In the region
a ≤ x ≤ w, its wave function is ψ2(x) = ##(x − d)^2 − c##. For
x ≥ w, ψ3(x) = 0. (a) By applying the continuity conditions
at x = a, find c and d in terms of a and b. (b) Find w in terms of
a and b.
Relevant Equations
ψ1(x) = ##−b(x^2 − a^2 )##. 0 ≤ x ≤ a
ψ2(x) = ##(x − d)^2 − c##. a ≤ x ≤ w
ψ3(x) = 0 x ≥ w
From my understanding, you can equate ψ1(x) and ψ2(x) at the boundary of x = a, so I plugged in the values of a into x for both equations and I got ψ1(x) = 0 and ψ2(x) = ## (a-d)^2-c ##. I am a bit stuck on where to go from here.
 
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Danielk010 said:
and I got ψ1(x) = 0 and ψ2(x) = ## (a-d)^2-c ##. I am a bit stuck on where to go from here.
No. You got ψ1(a) = 0 and ψ2(a) = ## (a-d)^2-c ##. Equating ψ1 and ψ2 at x=a means you have ψ1(a) = ψ2(a)

Then: what about continuity of the first derivative ?

##\ ##
 
BvU said:
No. You got ψ1(a) = 0 and ψ2(a) = ## (a-d)^2-c ##. Equating ψ1 and ψ2 at x=a means you have ψ1(a) = ψ2(a)

Then: what about continuity of the first derivative ?

##\ ##
The continuity for the first derivative of which wave function?
 
BvU said:
No. You got ψ1(a) = 0 and ψ2(a) = ## (a-d)^2-c ##. Equating ψ1 and ψ2 at x=a means you have ψ1(a) = ψ2(a)

Then: what about continuity of the first derivative ?

##\ ##
I got it. Thank you so much for the help
 
So is there some elegant way to do this or am I just supposed to follow my nose and sub the Taylor expansions for terms in the two boost matrices under the assumption ##v,w\ll 1##, then do three ugly matrix multiplications and get some horrifying kludge for ##R## and show that the product of ##R## and its transpose is the identity matrix with det(R)=1? Without loss of generality I made ##\mathbf{v}## point along the x-axis and since ##\mathbf{v}\cdot\mathbf{w} = 0## I set ##w_1 = 0## to...

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