Maple 2019 Questions and Posts

These are Posts and Questions associated with the product, Maple 2019

I am trying to use this command

plot({0, 2*x^2, 2*x^2 - 2*x^3 + 8/3*x^4 - 4*x^5}, x = -10 .. 10, color = ["DarkGreen", "CornflowerBlue", "Burgundy"])

However, only the last function is showing up. 0 and 2x^2 is not showing up. I can't change the axes sizes because then the last function disappears.

I have the following question, plot the graph of mu=5*log_10(D_L/10) where D_L=(c/H_0)*\int_0^z dz'/[A(1+z')^4+B(1+z)^3+C]^{1/2} with resepct to z, where A,B,C are numerical values given beforehand, and c is the speed of light and H_0 is the current Hubble constant.

 

Can someone please help with this simple plotting assignment.

 

Thanks, just by experience, can I learnt these syntax languages.

 

Peace out!

 

restart;
PDEtools[declare](f(x), prime = x);
N := 4;
f(x) :=  sum(p^i*f[i](x), i = 0..N):
HPMEq := (1 - p)*diff(f(x), x $ 3) + p*(diff(f(x), x $ 3) + 1/2*diff(f(x), x, x)*f(x));
for i from 0 to N do
    equ[1][i] := coeff(HPMEq, p, i) = 0;
end do;
cond[1][0] := f[0](0) = 0, D(f[0])(0) = 0, D(f[0])(5) = 1

for j to N do
    cond[1][j] := f[j](0) = 0, D(f[j])(0) = 0, D(f[j])(5) = 0;
end do

for i from 0 to N do
    dsolve({cond[1][i], equ[1][i]}, f[i](x));
    f[i](x) := rhs(%);
end do;
f(x) := evalf(simplify(sum(f[n](x), n = 0 .. N)))

convert(f(x), 'rational')

subs(x = 2.4, diff(f(x), x))

Prime_Derivative_Notation_for_Explicit_X_Values.mwPrime_Derivative_Notation_for_Explicit_X_Values.mw

## I hope this works. I can't seem to paste my MW file in this window in a readable format.

Hello all

could anyone tell how to solve following nonliner equations numerically.

f '''' - c1(g'') + R(f ' f '' - f f ''' )=0

g'' + c2(f '' -2g) -c3(f g' - f ' g)=0

f ' (-1)=0,   f ' (1)=0,   f(-1)=1-A, F(1) =1, g(-1)=0, g(1)=0

c1=3.2, c2=3.3, c3=3.4, R= -10 and A=1.6 are constants.   

please help to find solution  numerically and how to plot. 

Thanks in advence

 

I'm trying to arrange the constant terms of W(x). Like sinh (alpha*x) *(C2-C1).....and by defining C2-C1= D2 I want to rearrange the equation. Without this step, I'm not able to solve the equation further. I have also tried a few steps but it's not working.

Hello guys I do not have a Code for you I'm sorry for that. Mybe you can help me with my Task its in German but I need to find out the (x;y) for my Saddle Point and also the local Maxima (x;y). I hope you can help me. 

I am experimenting with using units especially for when there are awkard conversion factors. 

The document is for motor gearbox torques inertia ration and frequency.

I have documented my specific questions in the worksheet.

I am interested is see different ways of setting this up. Like I would rather setup the formulas at the start, then supply figures.


 

restart

``

with(Units[Natural])

UseSystem('SI')

UseSystem(SI)

(1)

Can I set the units for mass, accel, etc. so I don't have to re enter the default units if I change the figures later?

``

Mass := 3000*'kg'

3000*Units:-Unit(kg)

(2)

Accel := 1.5*'m'/'s'^2

1.5*Units:-Unit(m/s^2)

(3)

Rat := 5

5

(4)

``

Radius := (1/2)*(0.8282e-1-0.6e-2)*'m'

0.3841000000e-1*Units:-Unit(m)

(5)

Torque := Mass*Accel*Radius

172.8450000*Units:-Unit(J)

(6)

````

MotorTorque := Torque/Rat

34.56900000*Units:-Unit(J)

(7)

Jload := Mass*Radius^2

4.425984300*Units:-Unit(kg*m^2)

(8)

Jmtr := 1.42*10^(-2)*'kg'*'m'^2

0.1420000000e-1*Units:-Unit(kg*m^2)

(9)

Parse:-ConvertTo1D, "first argument to _Inert_ASSIGN must be assignable"

12.46756141

(10)

stiff := convert(48, 'units', 'N'*'m(radius)'/'arcmin', 'N'*'m(rarius)'/'rad', 'symbolic')

518400/Pi

(11)

/rad

518400/Pi

(12)

"(->)"

0.16501e6

(13)

``

Freq := sqrt(stiff/Jload)/(2*Pi)/s   i.e. Hertz

30.73072153*Units:-Unit(1/(kg^(1/2)*m))

(14)

stiff := 4567

4567

(15)

Freq

30.73072153*Units:-Unit(1/(kg^(1/2)*m))

(16)

``


 

Download Units_questions.mw

I have this problem, that maple wont isolate for x_1. I want to automate the prosses of any funktion, but how come it not work?

Hope you can help 

I want to shade the function y=x*ln(x) on the domain of (0,1].

f:= (ln(4x-4)/4)-(ln(4x+4)/4)+(arctan(x)/2)

When I do plots([f(x),f(x)-2,f(x)+2]), the graphs don't extend infinitely like I want. They stop just themselves. How get I the plots to extended more? I attached a picture. 

Hi,

I'm trying to solve for Double Inequality. (1.1) and (1.3) combined.

Thanks in Advance
 

Example: Solving a Double Inequality

 

-3 <= 6*x-1

0 <= 6*x+2

(1.1)

"(->)"

[[-1/3 <= x]]

(1.2)

6*x-1 < 3

6*x < 4

(1.3)

"(->)"[[x < 2/3]]

"ex1(x):=6 x-1"

proc (x) options operator, arrow, function_assign; 6*x-1 end proc

(1.4)

"->"

 

"->"

"ex2(y):=3"

proc (y) options operator, arrow, function_assign; 3 end proc

(1.5)

"ex3(y):=-3"

proc (y) options operator, arrow, function_assign; -3 end proc

(1.6)

NULL


 

Download Double_Inequality.mw

Hi!
I am trying to solve ODE with bvp[midrich], and I need to prove the validity of this method. 
Where can i read about realization of bvp[midrich]. What scheme does it use? Аre there any articles on this subject?
 

 

In Maple 2019.2, I'm trying to compute series expansions. For the input
series(1/z^4/(1-z), z=0, 1);
Maple gives me a series of the expression around z=0, truncated to 1 term, i.e.
z^(-4) + O(z^(-3))

But with the input
series(1/z^4/(1-z), z=0, 2);
Maple gives me the result
z^(-4) + z^(-3) + z^(-2) + z^(-1) + 1 + z + O(z^2)

Apparently Maple has decided not to give a series with 2 terms, but a series up to O(z^2). I'm surprised that the third argument of "series" is not treated in a consistent manner. I've restarted the Maple server between the two computations, so it's not a memory effect.

In the above example, this is just a minor annoyance, but I'm actually dealing with huge expressions, and for performance reasons it's important to truncate the series expansion at the desired order and stop further computations. Has anyone encountered this problem?

Can Maple solve a (simple) nonlinear diophantine equation with restrictions on the variables?

For example, I would like to solve simple equations where all values of the variables are positive integers.

I have tried isolve. For example:

isolve({29 = x^2 + y^2, 1 <= x, 1 <= y})

and

{isolve}({29 = x^2 + y^2, 1 <= x, 1 <= y})

but they just give a warning (and no solutions):

Warning, solutions may have been lost

 

First 17 18 19 20 21 22 23 Last Page 19 of 47