To make Preben's point even clearer, there is no need to even re-type the input in 1D

I copied the 2D output from your worksheet into a Maple 13  classic (1D) worksheet. This comes along with all the hard-to-read 2D formatting thus

T := `#mfrac(mi("RL"),mrow(mi("j"),mo("⋅"),mi("ω",fontstyle = "normal"),mo("⋅"),mi("Cp")),linethickness = "1")`/((RL+1/(j*omega*Cp))*(`#mfrac(mi("R"),mrow(mi("j"),mo("⋅"),mi("ω",fontstyle = "normal"),mo("⋅"),msub(mi("C"),mi("s"))),linethickness = "1")`/(R+1/(j*omega*`#msub(mi("C"),mi("s"))`))+`#mfrac(mi("RL"),mrow(mi("j"),mo("⋅"),mi("ω",fontstyle = "normal"),mo("⋅"),mi("Cp")),linethickness = "1")`/(RL+1/(j*omega*Cp))));

But if you then copy the output of this to the next line, you get this

T := RL/(j*omega*Cp*(RL+1/(j*omega*Cp))*(R/(j*omega*C[s]*(R+1/(j*omega*C[s])))+RL/(j*omega*Cp*(RL+1/(j*omega*Cp)))));

which then simplifies to

(R*j*omega*C[s]+1)*RL/(R*RL*j*omega*Cp+R+RL*R*j*omega*C[s]+RL)

 

I also never use anything else than 1D input, because I find 2D hard to deal with and I learned using 1D, so I also don't know why 2D doesn't work.

What I meant was, can you use the mouse to close/quit Maple after it freezes and does Maple generate any error message ?

Anyway, I think you need to contact Maplesoft technical support. My guess is that something went wrong in the installation.

What I meant was, can you use the mouse to close/quit Maple after it freezes and does Maple generate any error message ?

Anyway, I think you need to contact Maplesoft technical support. My guess is that something went wrong in the installation.

Ahh thanks.... the infamous frontend !  I've always had trouble getting my head around it ! The help pages are a bit terse - thanks for the link - I think I've managed it now. At least it gives me the result I expected. Here's an example of the kind of functional I'm dealing with 

z := exp(-x)*sqrt(y(x)-exp(x)*diff(y(x),x));

z1:=frontend(diff, [z,diff(y(x),x)],[{`*`, `+`, radical}]);

z2:=frontend(diff, [z,y(x)],[{`*`, `+`, radical}]);

z3:=diff(z1,x);

EL:=simplify(z3-z2);

VC:=VariationalCalculus[EulerLagrange](z,x,y(x));

is(VC[1]=EL);

is(VC[1]=-EL);

#...which was the whole point of doing this.

# Hooray !!

For completeness, here's how I did it with subs 

F := z;

F1:=subs(diff(y(x),x)=yp,F);          
F2:=subs(y(x)=y,F1);
F3:=diff(F2,y);
F4:=subs(y=y(x),F3);
F5:=subs(yp=diff(y(x),x),F4);  # This gives the partial wrt to y(x)  

# Then...
FF1:=diff(F1,yp);  
FF2:=subs(yp=diff(y(x),x),FF1); # This gives the partial wrt to diff(y(x),x)

# So now we can formulate the Euler-Lagrange equation:
FF3:=diff(FF2,x);  #This gives the derivative with respect to x of the partial derivative with respect to diff(y(x),x)
ELL:=simplify(FF3-F5);

is(EL=ELL);

# Hooray again !

Are there any other ways of doing this ? 

Ahh thanks.... the infamous frontend !  I've always had trouble getting my head around it ! The help pages are a bit terse - thanks for the link - I think I've managed it now. At least it gives me the result I expected. Here's an example of the kind of functional I'm dealing with 

z := exp(-x)*sqrt(y(x)-exp(x)*diff(y(x),x));

z1:=frontend(diff, [z,diff(y(x),x)],[{`*`, `+`, radical}]);

z2:=frontend(diff, [z,y(x)],[{`*`, `+`, radical}]);

z3:=diff(z1,x);

EL:=simplify(z3-z2);

VC:=VariationalCalculus[EulerLagrange](z,x,y(x));

is(VC[1]=EL);

is(VC[1]=-EL);

#...which was the whole point of doing this.

# Hooray !!

For completeness, here's how I did it with subs 

F := z;

F1:=subs(diff(y(x),x)=yp,F);          
F2:=subs(y(x)=y,F1);
F3:=diff(F2,y);
F4:=subs(y=y(x),F3);
F5:=subs(yp=diff(y(x),x),F4);  # This gives the partial wrt to y(x)  

# Then...
FF1:=diff(F1,yp);  
FF2:=subs(yp=diff(y(x),x),FF1); # This gives the partial wrt to diff(y(x),x)

# So now we can formulate the Euler-Lagrange equation:
FF3:=diff(FF2,x);  #This gives the derivative with respect to x of the partial derivative with respect to diff(y(x),x)
ELL:=simplify(FF3-F5);

is(EL=ELL);

# Hooray again !

Are there any other ways of doing this ? 

Well, I've managed to do this, using subs, to replace the y(x) and diff(y(x),x) with new variables, then doing the necessary differentiations and reversing out the subs, but it seems like a very awkward and contrived way to do it.

 

As a trivial example, suppose we have

F:=y(x)^2;

the I want to differentiate this to give 2y(x) without resorting to using subs to change the variable.

 

Is there a better way ?

Wow. Impressed.

Wow. Impressed.

Thanks Alec, as for Markov, it's Mr Markov Snr, born 1856. I wasn't aware (until just now) that his son of the same name was also a mathematician.

Thanks Alec, as for Markov, it's Mr Markov Snr, born 1856. I wasn't aware (until just now) that his son of the same name was also a mathematician.

I came close to getting a Toshiba (specs posted a few weeks ago above ) but the RAID options of the Sony SSD clinched it. The secondary factor was it being smaller/lighter (despite having a higher screen res).

After much procrastination, I finally settled on this Sony Vaio VPCZ117GGX Core i7-620M processor 2.66 GHz with Turbo Boost up to 3.33 GHz 8GB RAM Quad SSD with RAID 0: 256 GB or RAID 1: 128 GB (64 GB x 4) NVIDIA GeForce GT 330M CUDA 13.1" FullHD: 1920 x 1080 ; LED backlight US$ 2500

This is assessed homework. I think you need to be careful with what you are asking.

This is assessed homework. I think you need to be careful with what you are asking.

"The Dell technician recommended Fujitsu" !! Haha :-) I had a little look at Fujitsu and didn't like the specs. For another thing is they (and many others) don't offer SSD as an option, and if you do it yourself you invalidate the warranty (this is the main reason I'm staying away from Sony this time). I am a bit wary of Dell, having known several people including you who have had problems, though Dell is currently No2 on my list. They are known to have good customer service - of course that's not much of a consolation if your HDD packs up, but since I will be getting an SSD, not HDD, and assuming that SSDs are unlikely to fail after a reasonable burn it, the worst case scenario is that the LCD or motherboard fails, which will be swapped out by a friendly Fujitsu-recommending tech, then back up to speed with hopefully just a day or less of downtime and no need for reinstallations. I don't care what the thing looks like so IBM/Lenovo is also an option, but I think it's the same problem as with Fujitsu/Sony (ie SSD)