What do I need to do to the "2 + 3" in the attached Document in order to make it evaluate? I know about F5 to switch between Text and Math modes, but that's not enough to get me where I want to be. The "2 + 3" is already in Math mode, but that's not enough to get it to evaluate.

The Document: t.mw

Download Analisa_Dinamik_Limb_v1_(30).mwAnalisa_Dinamik_Limb_v1_(30).mw

So I have an equation that basically takes the component of vectors to be used as an equation. The variables that I after are FB1z, FB2x, and FB3y For example here is my equation:

EOM1:=(AFB1[1]+AFB2[1]+AFB3[1])=TEOM[1]

EOM2:=(AFB1[2]+AFB2[2]+AFB3[2])=TEOM[2]

EOM3:=(AFB1[3]+AFB2[3]+AFB3[3])-TEOM[3]:

FBBp1:=FBPP1=(EulP1[1]+EulP2[1]+EulP3[1]):

FBBp2:=FBPP2=(EulP1[2]+EulP2[2]+EulP3[2]):

FBBp3:=FBPP3=(EulP1[3]+EulP2[3]+EulP3[3]):

However there are unknown variable in AFB2[1] named FB2x and AFB3[1] named FB3y. Then AFB1[2] has unknown equation named FB1z and AFB3[2] has FB3y and so on. While in my FBBp1,FBBp2,and FBBp3 holds all of the variable of FB1z, FB2x, and FB3x

I have tried to use 'solve' command to find the variable but my computer won't stop processing it:

sls:=solve({EOM1,EOM2,EOM3,FBBp1,FBBp2,FBBp3},{FB1z,FB2x,FB3y}):

I tried to use the Gauss-Elimination by forming a matrix but it doesn't work as well since I am really confused how to take out the variables out of the vector component.

zzz:=Matrix([0,AFB2[1],AFB3[1],jjj[1]],[AFB1[2],0,AFB3[2],jjj[2]],[AFB1[3],AFB2[3],0,jjj[3]],[FBP1[1],FBP2[1],FBP3[1],EulP[1]],[FBP1[2],FBP2[2],FBP3[2],EulP[2]],[FBP1[3],FBP2[3],FBP3[3],EulP[3]]):

GaussElimination:=(zzz)

I would be very grateful If someone could help me. Thankyou

Edit: here are the .txt files and .mpl files that required to run the program

Inverse_Kinematics_ADRIAN2.mw

RotInertiax0_ADRIAN.txt

Download DisplacementXYZ.txt

inersia_platfrom.txt

There is an .mpl file that I couldn't upload so I will upload it in the comments

Etude d'un cas particulier
a := 5: b := 7:
k := 9:
A := [a, 0]: B := [0, b]: #A et B fixes
P := [t, 0]: Q := [0, k/t]:#P et Q 2 points mobiles
cir := -a*x-b*y+x^2+y^2 = 0:
sol := solve(subs(y = 5, cir), x):
cen := [solve(diff(cir, x)), solve(diff(cir, y))]:
x0 := sol[1]: y0 := 5:
M := [x0, y0]:
R := sqrt(cen[1]^2+cen[2]^2):
beta := arctan(diff(solve(EQ(M, cen), y), x)):
Recherche des valeurs de t pour que les 2 droites soient perpendiculaires
eq := t^2*(y0-b)+t*(a*b-a*y0+b*x0-k)-x0*(a*b-k) = 0;
sol := solve(eq, t);
t := sol[1]; tp := sol[2];
P1 := [t, 0]; Q1 := [0, k/t];
PQ1 := simplify(x*(-a*b+b*t+k)+y*t*(t-a)-t*(-a*b+b*t+k)) = 0:#1ere tangente
PQ2 := simplify(x*(-a*b+b*tp+k)+y*tp*(tp-a)-tp*(-a*b+b*tp+k)) = 0:#2ième tangente
P2 := [tp, 0]; Q2 := [0, k/tp];
CIR := implicitplot(cir, x = -4 .. 8, y = -4 .. 12, color = red);
Fig := proc (alpha) local Dr1, DR1, Dr2, DR2, N, u0, v0, Po, t, tp, sol; global a, b, k, cen, R; u0 := cen[1]+R*cos(alpha); v0 := cen[2]+R*sin(alpha); N := [u0, v0]; sol := solve(t^2*(v0-b)+t*(b*u0-a*v0+a*b-k)-u0*(a*b-k) = 0, t); t := sol[1]; tp := sol[2]; Dr1 := simplify(x*(-a*b+b*t+k)+y*t*(t-a)-t*(-a*b+b*t+k)) = 0; DR1 := implicitplot(Dr1, x = -4 .. 8, y = -4 .. 12, color = brown); Dr2 := simplify(x*(-a*b+b*tp+k)+y*tp*(tp-a)-tp*(-a*b+b*tp+k)) = 0; DR2 := implicitplot(Dr2, x = -4 .. 8, y = -4 .. 12, color = pink); Po := pointplot([N[]], symbol = solidcircle, color = [black], symbolsize = 8); display([Po, DR1, DR2]) end proc;
DrPQ1 := implicitplot(PQ1, x = -4 .. 22, y = -4 .. 12, color = blue);
DrPQ2 := implicitplot(PQ2, x = -4 .. 22, y = -4 .. 12, color = blue);
Points := pointplot([A[], B[], M[], P1[], P2[], Q1[], Q2[], cen[]], symbol = solidcircle, color = [green], symbolsize = 10);
T := plots:-textplot([[A[], "A"], [B[], "B"], [M[], "M"], [P1[], "P1"], [P2[], "P2"], [Q1[], "Q1"], [Q2[], "Q2"], [cen[], "cen"]], font = [times, 10], align = {below, left});
n := 19;
display([seq(Fig(2*i*Pi/n), i = 0 .. n), Fig(beta), CIR, DrPQ1, DrPQ2, Points, T], scaling = constrained, size = [500, 500]);
I would find out the focus of the ellipse. Thank you.

I'm trying to obtain the dynamical response of a simply-supported beam with a cantilever extension, coupled to a spring-mass system. In mathematical terms, this system is ruled by three PDEs (relative to each bare part of the main structure) and one ODE (relative to the spring-mass system). I think my mathemical model is finely formulated, but Maple keeps telling me this:

Error, (in pdsolve/numeric/process_IBCs) improper op or subscript selector

I believe it is because my PDEs depend on "x" and "t", while the ODE depends solely on "t". I have tried to transform my ODE into a "PDE", making it also dependent of "x", but without imposing any boundary conditions relative to "x". However, after this Maple points a new error message:

Error, (in pdsolve/numeric) initial/boundary conditions must be defined at one or two points for each independent variable

Could someone help me finding a solution? My algorythm in shown in the attached file below.

Worksheet.mw

Can anyone help me to frame the equations in Fractional Reduced Differential Transform Method

system of nonlinear ordinary diﬀerential equations

ds/ dt = b−γ s(t)− (δ s(t)(i(t) + βa(t)) /N − ε s(t) m(t)

de/ dt = δ (s(t)(i(t) + βa(t))/ N + ε s(t) m(t) − (1−ϑ) θ e(t) − ϑ α e(t) − γ e(t)

di/ dt = (1−ϑ) θ e(t) − (ρ + γ) i(t)

da/ dt = ϑ α e(t) − (σ + γ) a(t)

dr /dt = ρ i(t) + σ a(t) − γ r(t)

dm /dt = τ i(t) + κ a(t) − ω m(t)

Download SC-plots.mw

I am having difficulty getting solutions to a pair of PDEs. Would anyone like to cast an eye over the attached file, incase I am missing something.

Thanks

Melvin

Hello,

For a few days Maple crashs everytime i try to use the command "plot3d()".

I had'nt this problem befor and I have no idea what the reason could be. It ist irrelevant what Funktion I try to visualize, the window just get closed evertime.

I hope someone can help me.

Thank you!

Tom

Hello

In this example, we have the KdV equation

t] - 6 uux] + xxx] = 0

I would like to find the Lax pair for the KdV equation, which are

Lψ=λψ

ψ[t] = Mψ

Lt+ML-LM = 0 called a compatibility condition

So, I will start from this purpose

Then we will assume M in the form

will assume M in the form

M := a3*Dx^3+a^2+a1*Dx+a0

thenb using M and L in the for L[tL-LM = 0can find

Dx^5+( ) Dx^4+( ) Dx^3+( ) Dx^2+( ) Dx+( )=0

then wean find a_i =0,1,2,3

In the following maple code to do that

my question is

.How I canoue the soluo get a_i2,3 usinmaple code

any maple packge to find Lax pair for PDE -

Download find_lax_pair.mw

I am studying the motion of a beam coupled to piezoelectric strips. This continuous system is modelled by two DE:

`YI*diff(w(x,t), x$4)-N[0]*cos(2*omega*t)*diff(w(x,t), x$2)+c*diff(w(x,t), t)+`ρA`*diff(w(x,t), t$2)+C[em,m]*v(t) = 0;`

And:

`C[p]*diff(v(t), t)+1/R[l]*v(t) = C[em,e]*(D[1,2](w)(0,t)-D[1,2](w)(ell,t));`

where "w(x,t)" stands for the beam's vibration and "v(t)" means the electric voltage, which is constant throught the beam. I would like to numerically solve both DE simultaneosly, but maple will not let me do it. I would like to know why. I am getting the following error:

`Error, (in pdsolve/numeric/process_PDEs) number of dependent variables and number of PDE must be the same`

I suppose it is because "w(x,t)" depends on "x" and "t", while "v(t)" depends solely on time, but I am not sure. Could someone help me out? Here is my current code:

restart:
with(PDEtools):
declare(w(x,t), v(t)):
YI*diff(w(x,t), x$4)-N[0]*cos(2*omega*t)*diff(w(x,t), x$2)+c*diff(w(x,t), t)+`ρA`*diff(w(x,t), t$2)+C[em,m]*v(t) = 0;
pde1:= subs([YI = 1e4, N[0] = 5e3, c = 300, omega = 3.2233993, C[em,m] = 1], %):
ibc1:= w(0,t) = 0, D[1,1](w)(0,t) = 0, w(ell,t) = 0, D[1,1](w)(ell,t) = 0, D[2](w)(x,0) = 0, w(x,0) = sin(Pi*x/ell):
C[p]*diff(v(t), t)+1/R[l]*v(t) = C[em,e]*(D[1,2](w)(0,t)-D[1,2](w)(ell,t));
pde2:= subs([C[p] = 10, R[l] = 1000, C[em,e] = 1, ell = 5], %):
ibc2:= v(0) = 0:
pdsolve({pde1, pde2}, {ibc1, ibc2}, numeric);

Thanks.