## How do I correct the exact solution in this code?...

I have written the following attached code to use Euler explicit method to solve the following IVP

```diff(y(x), x) = 2*(1+x)-y(x), y(2) = 5
With Exact solution  y(x) = 2*x+exp(-x)/exp(-2)
```

However, I found out that my exact results are not correct while the numerical results are okay. What have I done wrong in the code? Can someone modify the code?

Thank you and kind regards.

## Performance discriminant procedure...

Hi all, we know Maple provided discrim method to find discriminant of a polynomial

I want to write a similar method with independent variable is ,... my code is below

Some examples

Maple already similar method? If not have, we can improve performance it?

Thank you very much.

## How to take expectation of function of random vari...

Hi,

I have a random variable that follows Uniform(1,4). Now I have a function which is of the following type:

g := a*alpha+b*t/alpha+exp(alpha)

where,

A := RandomVariable(Uniform(c, d));
RandomVariable(Uniform(c, d))
f := proc (alpha) options operator, arrow; PDF(A, alpha) end proc;
alpha -> PDF(A, alpha)
#Defining expectation fuction
E := proc (alpha) options operator, arrow; int(alpha*f(alpha), alpha = c .. d) end proc;
alpha -> int(alpha f(alpha), alpha = c .. d)
#g is a function of random variable &alpha;, where a and b are parameter

now I want to find the expectation of g and the first derivative of expectation of g,

E(g)

diff(E(g), t)

I understand the way I have defined E(alpha) is improper. But please understand my intent and help! here is the maple file also doubt_1.mw

## How to specify the number of points to show on a c...

Dear all,

Please I want only 8 points to show on this curve, how do I specify it?

plot(ln(1+sin(Pi*x)), x = 0 .. 1, legend = numerical, style = point, symbol = box, color = blue, symbolsize = 15, numpoints = 8);

Thank you all and kind regards.

Please do keep safe amidst this global pandemic.

## Plot Variable confusion...

In my worksheet today my intention was to compare the least squares linear regression for three datasets as indicated, but when I right click on the output as seen in the bottom line to select the plot type, all options state there to be independant variables K[0] and K[1], where as the output displays only the variable K as I intended, which part of my code is creating this confusion for maple?

Worksheet Specific Investigation Content

 >
 >
 >
 >
 >
 (1.1)
 >

## Error, missing operator or `;`...

Hi,

I am writing the following code and MAPLE is giving me operator error. Please help (file: doubt_6.mw)

d2:=100000000

for m in set_m do
for n in set_n do
SOL1 := fsolve({ODE11, ODE12}, {N, t__2});
N1:=eval(N,SOL1);
t_2_1 :=eval(t__2,SOL1);
T_1:= eval(T, [lambda = 3, a = 300, b = .15, c = .25, A__m = 300, A__d = 150, A__r = 50,C__m = 4, P__m = 8, P__d = 10,
P__r = 12, theta__m = .15, theta__d = .12, theta__r = 0.5e-1, h__m = .2, h__d = .3, h__r = .5, i__m = .1, i__d = .1,
i__r = .1, i__om = .1, i__OD = .15, i__c = .3, i__e = .2, M = 2, alpha = 0.2e-1, t__2 = t_2_1]):
t_31:= T_1 /m ;
t_41:= T_1 /(m*n) ;
if (N1<=t_41 and 2>=t_31) then
d1:= eval(TCS__1, [lambda = 3, a = 300, b = .15, c = .25, A__m = 300, A__d = 150, A__r = 50, C__m = 4, P__m = 8,
P__d = 10, P__r = 12, theta__m = .15, theta__d = .12, theta__r = 0.5e-1, h__m = .2, h__d = .3, h__r = .5, i__m = .1,
i__d = .1, i__r = .1, i__om = .1, i__OD = .15, i__c = .3, i__e = .2, M = 2, alpha = 0.2e-1, t__2=t_2_1, N=N1]):
if (d1<= d2) then
d2:= d1;
print("Value is updated",d2,N1,t_2_1,"for",m,n)
end if
end if
print(N1,t_2_1,t_31,t_41,d1,m,n)
end do
end do

## Error, (in LinearAlgebra:-Determinant) matrix mus...

hi

I'm working on my thesis,to solve a particular problem,I created a 84*84 matrix in Matlab.

I want to calculate the determinat of that matrix in maple,so from tools>assistance>import date added this matrix in maple.

every thing seems to be ok but when i want to caculate the determinant this error apears :

Error, (in LinearAlgebra:-Determinant) matrix must be square

does anybody know what is the problem here?

Also sorry for my weak English

and it's worth mentioning that I'm a beginner in maple programming

thank you

## how to extract variables value from fsolve in code...

doubt5.mw

Hi I want to run the following algorithm in code edit region:

for m in set_m do
for n in set_n do
solve for N solving ODE11 and ODE12 simultaneously
solve for t_2 solving ODE11 and ODE12 simultaneouly
find t__3 and t__4
if (N<=t_4 and M>=t_3) then
d1= TCS__1 using n,m,t__2 and N
if (d1< d2)
d2=d1
print(d2,m,n,N,t_2)
end do
end do

But I am struck for to how to extract N and t__2 from SOL1 in code edit region

SOL1 := fsolve({ODE11, ODE12}, {N, t__2});

## exp(0) is not showing as 1...

doubt4.mw

Hi, As shown in the figure(red color). I am not able to understand why Exp(0) is not showing as 1. As evaluating rules of maple says that it evaluates everything till it gets unassigned variables.

Do I am doing something wrong? There is a link to the file.

## Error, invalid input: solve expects its 1st argume...

doubt_3.mw

Hi, I am trying to do a simple think like

od2 := diff(x^3, x)+v+2 = 0

od3 := diff(v^2, v)+x+4 = 0

solve({(1),(2)},{x,v})

but with my code,  I am doing the exact same but getting the following error

Error, invalid input: solve expects its 1st argument, eqs, to be of type {`and`, `not`, `or`, algebraic, relation(algebraic), ({list, set})({`and`, `not`, `or`, algebraic, relation(algebraic)})}, but received {[1316.872428*(-0.1500000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+3.000000*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.2250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.2304687500e-6*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.3662109374e-8*t__2^4*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^4*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.5320312500e-4*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-3.000000)*exp(-0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(int(.2*(.1*t+1)*i__m2(t), t = 0 .. t__2))/N^.98-11.76000000/(N^.98*((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2))+1185.185185*(-0.1953125000e-5*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.4898437500e-3*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.7500000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+6.0000*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-6.0000)*exp(-0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))/(N^.98*((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2))+6.00*(-75.50000000*N^2.02+45.45000000*N^1.02+306.00*N^0.2e-1)/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)-1.200000000/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)-9.6*(-75.37500000*N^3.02+45.30000000*N^2.02+303.00*N^1.02)/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)] = 0, [-650*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2+65843.62140*N^0.2e-1*(-0.6750000000e-3*t__2^2-0.1350000000e-1*t__2+0.7500000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`-0.9000000000e-1-0.1500000000e-1*t__2*(0.900e-1*t__2+.90)+3.000000*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.2250000000e-1*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.2250000000e-1*t__2*(0.900e-1*t__2+.90)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.2250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.6914062500e-6*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.6914062500e-6*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(0.900e-1*t__2+.90)+0.2304687500e-6*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.1464843750e-7*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^4*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.1464843750e-7*t__2^4*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(0.900e-1*t__2+.90)-0.3662109374e-8*t__2^4*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^4*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.1064062500e-3*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.1064062500e-3*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(0.900e-1*t__2+.90)+0.5320312500e-4*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)))*exp(-0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(int(.2*(.1*t+1)*i__m2(t), t = 0 .. t__2))+65843.62140*N^0.2e-1*(-0.1500000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+3.000000*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.2250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.2304687500e-6*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.3662109374e-8*t__2^4*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^4*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.5320312500e-4*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-3.000000)*(-0.5625000000e-3*t__2^2-0.1125000000e-1*t__2+0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`-0.7500000000e-1-0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(-0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(int(.2*(.1*t+1)*i__m2(t), t = 0 .. t__2))+13168.72428*N^0.2e-1*(-0.1500000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+3.000000*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.2250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.2304687500e-6*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.3662109374e-8*t__2^4*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^4*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.5320312500e-4*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-3.000000)*exp(-0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(.1*t__2+1)*i__m2(t__2)+588.0000000*N^0.2e-1*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2+.60*(98765.43210*N^0.2e-1*(-0.5859375000e-5*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.5859375000e-5*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(0.900e-1*t__2+.90)-0.1953125000e-5*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.9796875000e-3*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.9796875000e-3*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))*(0.900e-1*t__2+.90)+0.4898437500e-3*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.7500000000e-1*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.7500000000e-1*t__2*(0.900e-1*t__2+.90)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.7500000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+6.0000*(0.5625000000e-3*t__2^2+0.1125000000e-1*t__2-0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+0.7500000000e-1+0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)))*exp(-0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+98765.43210*N^0.2e-1*(-0.1953125000e-5*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.4898437500e-3*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.7500000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+6.0000*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-6.0000)*(-0.5625000000e-3*t__2^2-0.1125000000e-1*t__2+0.6250000000e-2*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`-0.7500000000e-1-0.1250000000e-1*t__2*(0.900e-1*t__2+.90))*exp(-0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+i__m2(t__2))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)-.60*(98765.43210*N^0.2e-1*(-0.1953125000e-5*t__2^3*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^3*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+0.4898437500e-3*t__2^2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)^2*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-0.7500000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+6.0000*exp(0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))-6.0000)*exp(-0.1250000000e-1*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6))+int(i__m2(t), t = 0 .. t__2))*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2-(0.1500000000e-2*T^2+0.3000000000e-1*T)*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2-6.00*(-25.00000000*N^3.02+22.50000000*N^2.02+300*N^1.02)*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2-.1700000000*T*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2-2.4*(.1000000000*T-.2000000000)*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2-4*(0.1562500000e-3*T^2+0.1250000000e-1*T)*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2-12.0*(0.2500000000e-1*T-.1000000000*N)*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2+9.6*(-18.75000000*N^4.02+15.00000000*N^3.02+150*N^2.02)*(0.3750000000e-2*t__2^2+0.7500000000e-1*t__2-0.4166666667e-1*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+3/2+(1/12)*t__2*(0.900e-1*t__2+.90))/((1/12)*t__2*(0.450e-1*t__2^2+.90*t__2-.50*`#msup(msub(mi("\`t"),mi("2\`")),mn("2"))`+6)+t__2)^2] = 0}

## How to plot on the same graph continuous curve fo...

Hi, I am working on a bification diagram and was wondering if there is a way to plot the stable and unstable curves onto one figure.

I have two curves, if the eq1<eq2 I would like to indicate when this happens, with a dashed line.

When eq1>eq3 I would like to indicate this with a soild line.

implicitplot, x[m] vs x[u] with axis[2]=[mode=log]

r:=0.927: K:=1.8182*10^8:d[v]:=0.0038:d[u]:=2: delta:=1: p[m]:=2.5: M:=10^4: p[e]:=0.4: d[e]:=0.1: d[t]:=5*10^(-9): omega:=2.042: b:=1000: h[e]:=1000:h[u]:=1:h[v]:=10^4:

eq1 := r*d[t]*h[e]*x[u]^3+(r*h[e]*(-K*d[t]+d[t]*h[v]+d[e])+r*p[e]*x[m])*x[u]^2+(r*h[e]*(-K*d[t]*h[v]-K*d[e]+d[e]*h[v])+K*p[e]*(d[u]-r)*x[m])*x[u]-r*K*h[e]*d[e]*h[v];

eq2 := (d[t]*x[u]+d[e])*(2*r*x[u]/K+d[u]*p[e]*x[m]*x[u]/((h[v]+x[u])*(d[t]*x[u]+d[e])*(h[e]+p[e]*x[m]*x[u]/((h[v]+x[u])*(d[t]*x[u]+d[e]))))-r)+d[u]*h[e]*x[u]*(p[e]*h[v]*x[m]/(h[v]+x[u])^2-d[t]*p[e]*x[m]*x[u]/((h[v]+x[u])*(d[t]*x[u]+d[e])))/(h[e]+p[e]*x[m]*x[u]/((h[v]+x[u])*(d[t]*x[u]+d[e])))^2

## Error, equation is non-algebraic...

Hi, am trying to differentiate the following eq w.r.t t2 and N. But in t2 I am getting zero and in wrt N, an Error (non-algebraic expressions cannot be differentiated). But according to the article, I am following expression should come.

I am differentiating following

TCS := proc (N, T, m, n) options operator, arrow; piecewise(M <= t__3 and N <= t__4, TCS__1, M <= t__3 and t__4 < N, TCS__2, t__3 <= M and N <= t__4, TCS__3, `t__3 ` <= M and t__4 < N, TCS__4) end proc

ode5 := diff(proc (N, T, m, n) options operator, arrow; piecewise(M <= t__3 and N <= t__4, TCS__1, M <= t__3 and t__4 < N, TCS__2, t__3 <= M and N <= t__4, TCS__3, `t__3 ` <= M and t__4 < N, TCS__4) end proc, t__2) = 0

ode6 := diff(proc (N, T, m, n) options operator, arrow; piecewise(M <= t__3 and N <= t__4, TCS__1, M <= t__3 and t__4 < N, TCS__2, t__3 <= M and N <= t__4, TCS__3, `t__3 ` <= M and t__4 < N, TCS__4) end proc, N) = 0

Error, non-algebraic expressions cannot be differentiated

following are the pre-requisite to use above (also in the attachment doubt_2.mw)

i__m1(t) = ((-c*t^2*theta__m^2+b*t*theta__m^2+2*c*t*theta__m-b*theta__m+theta__m^2-2*c)*exp(theta__m*t)*a*N^alpha*(lambda-1)/theta__m^3-(-b*theta__m+theta__m^2-2*c)*a*N^alpha*(lambda-1)/theta__m^3)*exp(-theta__m*t)

i__m2(t) = (-(-c*t^2*theta__m^2+b*t*theta__m^2+2*c*t*theta__m-b*theta__m+theta__m^2-2*c)*exp(theta__m*t)*a*N^alpha/theta__m^3+(-c*t__2^2*theta__m^2+b*t__2*theta__m^2+2*c*t__2*theta__m-b*theta__m+theta__m^2-2*c)*exp(theta__m*t__2)*a*N^alpha/theta__m^3)*exp(-theta__m*t)

TC__m := A__m/(t__1+t__2)+(int(h__m*(i__m*t+1)*i__m1(t), t = 0 .. t__1))*(int(h__m*(i__m*t+1)*i__m2(t), t = 0 .. t__2))+P__m*I__om*m*(-(1/3)*a*c*N^alpha*M^3+(1/2)*a*b*N^alpha*M^2+a*N^alpha*M)/(t__1+t__2)+C__m*theta__m*(int(i__m1(t), t = 0 .. t__1)+int(i__m2(t), t = 0 .. t__2))/(t__1+t__2)

i__d(t) = (-(-c*t^2*theta__d^2+b*t*theta__d^2+2*c*t*theta__d-b*theta__d+theta__d^2-2*c)*a*N^alpha*exp(theta__d*t)/theta__d^3+(-c*t__3^2*theta__d^2+b*t__3*theta__d^2+2*c*t__3*theta__d-b*theta__d+theta__d^2-2*c)*a*N^alpha*exp(theta__d*t__3)/theta__d^3)*exp(-theta__d*t)

TC__d1 := A__d*m/(t__1+t__2)+m*(int(h__d*(i__d*t+1)*i__d(t), t = 0 .. t__3))/(t__1+t__2)+P__d*I__OD*m*n*(-(1/3)*a*c*N^alpha*N^3+(1/2)*a*b*N^alpha*N^2+a*N^alpha*N)/(t__1+t__2)+P__m*theta__m*m*(int(i__d(t), t = 0 .. t__3))/(t__1+t__2)+P__m*I__c*m*(int(i__d(t), t = M .. t__3))/(t__1+t__2)-P__d*I__e*m*(-(1/3)*a*c*N^alpha*M^3+(1/2)*a*b*N^alpha*M^2+a*N^alpha*M)/(t__1+t__2)

TC__d2 := A__d*m/(t__1+t__2)+m*(int(h__d*(i__d*t+1)*i__d(t), t = 0 .. t__3))/(t__1+t__2)+P__d*I__OD*m*n*(-(1/3)*a*c*N^alpha*N^3+(1/2)*a*b*N^alpha*N^2+a*N^alpha*N)/(t__1+t__2)+P__m*theta__m*m*(int(i__d(t), t = 0 .. t__3))/(t__1+t__2)-P__d*I__e*m*(-(1/4)*a*c*N^alpha*t__3^4+(1/3)*a*b*N^alpha*t__3^3+(1/2)*a*N^alpha*t__3^2+M-t__3-(1/3)*a*c*N^alpha*t__3^3+(1/2)*a*b*N^alpha*t__3^2+a*N^alpha*t__3)/(t__1+t__2)

i__r(t) = (-(-c*t^2*theta__r^2+b*t*theta__r^2+2*c*t*theta__r-b*theta__r+theta__r^2-2*c)*a*N^alpha*exp(theta__r*t)/theta__r^3+(-c*t__4^2*theta__r^2+b*t__4*theta__r^2+2*c*t__4*theta__r-b*theta__r+theta__r^2-2*c)*a*N^alpha*exp(theta__r*t__4)/theta__r^3)*exp(-theta__r*t)

TC__r1 := A__r*m*n/(t__1+t__2)+m*n*(int(h__r*(i__r*t+1)*i__r(t), t = 0 .. t__4))/(t__1+t__2)+P__d*theta__r*m*n*(int(i__r(t), t = 0 .. t__4))/(t__1+t__2)+P__d*I__c*m*n*(int(i__r(t), t = N .. t__4))/(t__1+t__2)-P__r*I__e*m*n*(-(1/4)*a*c*N^alpha*N^4+(1/3)*a*b*N^alpha*N^3+(1/2)*a*N^alpha*N^2)/(t__1+t__2)

TC__r2 := A__r*m*n/(t__1+t__2)+m*n*(int(h__r*(i__r*t+1)*i__r(t), t = 0 .. t__4))/(t__1+t__2)+P__d*theta__r*m*n*(int(i__r(t), t = 0 .. t__4))/(t__1+t__2)-P__r*I__e*m*n*(-(1/4)*a*c*N^alpha*t__4^4+(1/3)*a*b*N^alpha*t__4^3+(1/2)*a*N^alpha*t__4^2+N-t__4-(1/3)*a*c*N^alpha*t__4^3+(1/2)*a*b*N^alpha*t__4^2+a*N^alpha*t__4)/(t__1+t__2)

TCS__1 := TC__m+TC__d1+TC__r1

TCS__2 := TC__m+TC__d1+TC__r2

TCS__3 := TC__m+TC__d2+TC__r1

TCS__4 := TC__m+TC__d2+TC__r2

## How to resolve: Warning, solutions may have been l...

Hi, I am trying to solve two simultaneous equations (for t1) they are as follows-

eq 1

i__m2(0) = (-(-b*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`+`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^2-2*c)*exp(0)*a*N^alpha/`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^3+(-c*t__2^2*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^2+b*t__2*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^2+2*c*t__2*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`-b*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`+`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^2-2*c)*exp(`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`*t__2)*a*N^alpha/`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^3)*exp(0)

eq 2

i__m1(t__1) = ((-c*t__1^2*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^2+b*t__1*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^2+2*c*t__1*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`-b*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`+`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^2-2*c)*exp(`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`*t__1)*a*N^alpha*(lambda-1)/`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^3-(-b*`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`+`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^2-2*c)*a*N^alpha*(lambda-1)/`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`^3)*exp(-`#msub(mi("&theta;",fontstyle = "normal"),mi("m"))`*t__1)

rhs(i__m2(0) = (-(-b*theta__m+theta__m^2-2*c)*exp(0)*a*N^alpha/theta__m^3+(-c*t__2^2*theta__m^2+b*t__2*theta__m^2+2*c*t__2*theta__m-b*theta__m+theta__m^2-2*c)*exp(theta__m*t__2)*a*N^alpha/theta__m^3)*exp(0)) = rhs(i__m1(t__1) = ((-c*t__1^2*theta__m^2+b*t__1*theta__m^2+2*c*t__1*theta__m-b*theta__m+theta__m^2-2*c)*exp(theta__m*t__1)*a*N^alpha*(lambda-1)/theta__m^3-(-b*theta__m+theta__m^2-2*c)*a*N^alpha*(lambda-1)/theta__m^3)*exp(-theta__m*t__1))

solve({-(-b*theta__m+theta__m^2-2*c)*a*N^alpha/theta__m^3+(-c*t__2^2*theta__m^2+b*t__2*theta__m^2+2*c*t__2*theta__m-b*theta__m+theta__m^2-2*c)*exp(theta__m*t__2)*a*N^alpha/theta__m^3 = ((-c*t__1^2*theta__m^2+b*t__1*theta__m^2+2*c*t__1*theta__m-b*theta__m+theta__m^2-2*c)*exp(theta__m*t__1)*a*N^alpha*(lambda-1)/theta__m^3-(-b*theta__m+theta__m^2-2*c)*a*N^alpha*(lambda-1)/theta__m^3)*exp(-theta__m*t__1)}, [t__1]);
Warning, solutions may have been lost

## How do I solved PDE using non classical numerical ...

Dear All.

I hope we are all staying safe.

Please I want to solve Sine Gordon Equation using a numerical method I constructed (non-classical), I need to compare the result of the method with the exact solution to generate the errors. However, since the exact solution has two variables, x, and t, I really don't know how to accommodate the two in my coding.

Can someone be of help in this regard?

Thank you and kind regards