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Hey guys,

I'm gonna be honest and say I'm so stuck on this assignment - I really need help!

I've took on a third year computational physics course last year - turn your weaknesses into strengths someone told me.

Well, I failed and I'm back doing it again this year!

So, I just have to pass which means I need 30% in this assignment. But, I'm not getting there on my own - I've struggled to get to grips with the module - I got 20% in my last assignment :'(

Can someone help guide me through it?

So, I've already solved a

u''(x) = f(x) = - exp(x) * (-2 + 2x + 5x

Now I have to solve it for:

u'' + 500*exp(-100*x

I guess I rearrange so:

u'' = u

and then solve that

How do I solve it with an x and a u in the equation :O :(

If you've made it this far I love you and please help me, I have until next Wednesday to get this done and I can't do it on my own.............. pleeeeeease help I just need 30 damn percent

I attached a copy of the assignment

Leon

I'm gonna be honest and say I'm so stuck on this assignment - I really need help!

I've took on a third year computational physics course last year - turn your weaknesses into strengths someone told me.

Well, I failed and I'm back doing it again this year!

So, I just have to pass which means I need 30% in this assignment. But, I'm not getting there on my own - I've struggled to get to grips with the module - I got 20% in my last assignment :'(

Can someone help guide me through it?

So, I've already solved a

*similar*problem, the one I did was:u''(x) = f(x) = - exp(x) * (-2 + 2x + 5x

^{2}+ x^{3})
Code:

```
from pylab import *
from scipy import interpolate
def EllipticSolver(Nx):
dx = 1.0/Nx
pts = linspace(-dx/2.0,1.+dx/2.0,Nx+2)
soln = zeros(Nx+2)
rhs = zeros(Nx+2)
rhs = -exp(pts)*(-2.0 + 2.*pts + 5.*pts**2 + pts**3)
soln = tridiagonal2(soln,rhs,dx)
return pts[1:-1], soln[1:-1]
def tridiagonal2(dat,d,dx):
N = len(dat)
print(N)
dx2 = 1.0/(dx*dx)
a = zeros(N)
b = zeros(N)
c = zeros(N)
a[:] = dx2
c[:] = dx2
b[:] = -2.0*dx2
b[1] = -1.0*dx2
b[N-2] = -3.0*dx2
c[1] = c[1]/b[1]
d[1] = d[1]/b[1]
for j in range(2,N-1):
c[j] = c[j]/(b[j] - c[j-1]*a[j])
d[j] = (d[j] - d[j-1]*a[j])/(b[j] - c[j-1]*a[j])
print(a)
print(b)
print(c)
print(d)
dat[N-2] = d[N-2]
for j in range(N-3,0,-1):
dat[j] = d[j] - c[j]*dat[j+1]
return dat
x1, soln1 = EllipticSolver(100)
x2, soln2 = EllipticSolver(200)
x3, soln3 = EllipticSolver(400)
figure(1)
clf()
plot(x1,soln1,'r-')
plot(x2,soln2,'g-')
s2 = interpolate.interp1d(x2,soln2,'cubic')
soln2a = s2(x1)
s3 = interpolate.interp1d(x3,soln3,'cubic')
soln3a = s3(x2)
diff1 = soln1 - soln2a
diff2 = soln2 - soln3a
figure(2)
clf()
plot(x1,diff1,'r-')
plot(x2,4.*diff2,'g-')
```

Now I have to solve it for:

u'' + 500*exp(-100*x

^{2}) - u^{3}= 0I guess I rearrange so:

u'' = u

^{3}- 500*exp(-100*x^{2})and then solve that

How do I solve it with an x and a u in the equation :O :(

If you've made it this far I love you and please help me, I have until next Wednesday to get this done and I can't do it on my own.............. pleeeeeease help I just need 30 damn percent

I attached a copy of the assignment

Leon