Maple 2020 Questions and Posts

These are Posts and Questions associated with the product, Maple 2020

I do not understand why what I do in my first example does not work in the problem of integral. Can anyone help me? Thank you very much!

 

restart

assume(x > 0)

solve(x^2+3*x-4 = 0, x)

Warning, solve may be ignoring assumptions on the input variables.

 

1, -4

(1)

solve(x^2+3*x-4 = 0, x, UseAssumptions)

1

(2)
   

Download First_example_Maple.mw

 
 
 

f := proc (x) options operator, arrow; sin(100/(x+13)) end proc

proc (x) options operator, arrow; sin(100/(x+13)) end proc

(2.1.1)

g := proc (x) options operator, arrow; 10/(10*x+3) end proc

proc (x) options operator, arrow; 10/(10*x+3) end proc

(2.1.2)
   
 

A := fsolve(f(x) = g(x), x = 1.1)

1.049742001

(2.2.1)

B := fsolve(f(x) = g(x), x = 1.7)

1.676209051

(2.2.2)

C := fsolve(f(x) = g(x), x = 20)

19.35519742

(2.2.3)

 

 

assume(E > C)

solve(int(f(x)-g(x), x = C .. E) = 3, E, UseAssumptions)

Error, (in depends) too many levels of recursion

 

fsolve(int(f(x)-g(x), x = C .. E) = 3, E)

12.00027508

(2.3.1)

fsolve(int(f(x)-g(x), x = C .. E) = 3, E = 30)

28.05987548

(2.3.2)

La valeur de E cherchée est donc d'environ 28,06 unités.

Download Problem_of_integral.mw

This worksheet has an error when executing EulerLagrange.

How can this error be avoided?

Spring_Pendulum.mw

Hi

I am trying to get a family of curves on one graph. Each curve a different colour and labeled

P=2, Q=0 , P=2,Q=1 , etc

mmcdara 's proposal for inspiration?

https://www.mapleprimes.com/questions/233088-How-Do-I-Plot-A-Function-Of-Two-Variables

Family_of_curves_plot.mw

Hello there, 

When I tried to write an expression with the '1d' subscript, I found that it was automatically translated as '1.'. The following worksheet shows an example. Is there any chance to preserve the expression as I intended to see?

restart;

eq3_130:= Psi[fd] = L[ffd]*i[fd]+L[f1d]*i[1d]-L[ad]*i[d];

Psi[fd] = -L[ad]*i[d]+L[f1d]*i[1.]+L[ffd]*i[fd]

(1)

 

Download Q20220121.mw

I have just come across this curious but really boring problem.
In the code snippet below, expr1 and expr2 are identical.

restart:
data := [a=1, b=2]:
convert(
  piecewise(And(x(t) > a, x(t) < b), 1, 0),
  Heaviside
):
expr1 := eval(eval(%, data),  x(t)=z):
plot(expr1, z=0..3);


convert(
  piecewise(And(z > a, z< b), 1, 0),
  Heaviside
):
expr2 := eval(%, data),:
plot(expr2, z=0..3);


But if I change the parameterization of the problem, expr2 is still correct but expr1 is not

restart:
data := [d=1.5, a=0.5]:
convert(
  piecewise(And(x(t) > d-a, x(t) < d+a), 1, 0),
  Heaviside
):
expr1 := eval(eval(%, data),  x(t)=z):
plot(expr1, z=0..3);


convert(
  piecewise(And(z > d-a, z< d+a), 1, 0),
  Heaviside
):
expr2 := eval(%, data),:
plot(expr2, z=0..3);

Where does this come from?

PS: I'm sorry not to be able loading the mw file

Hello there, 

Would you allow me to ask these two questions?

1) is there any way to collect the expression 'eq14_2' w.r.t. DeltaP? The question is labeled as 'Q1' in the worksheet. 

2) Why does the 'DeltaP' term survive at the RHS of the expression 'eq14_2_3'? In other words, is it possible to cancel out the same term, 'DeltaP', in numerator and denominator?

restart;

eq14_1_3 := w[NET] = Delta*T[Sfg];

w[NET] = Delta*T[Sfg]

(1)

eq14_2 := w[NET] = -((v[2] + v[3])/2)((-DeltaP + P) - P) - ((v[1] + v[4])/2)((P - P) + DeltaP);

w[NET] = -(1/2)*v[2](-DeltaP)-(1/2)*v[3](-DeltaP)-(1/2)*v[1](DeltaP)-(1/2)*v[4](DeltaP)

(2)

simplify(eq14_2);

w[NET] = -(1/2)*v[2](-DeltaP)-(1/2)*v[3](-DeltaP)-(1/2)*v[1](DeltaP)-(1/2)*v[4](DeltaP)

(3)

collect(expand(eq14_2), DeltaP, distributed); # Q1

w[NET] = -(1/2)*v[2](-DeltaP)-(1/2)*v[3](-DeltaP)-(1/2)*v[1](DeltaP)-(1/2)*v[4](DeltaP)

(4)

Desired1 := w[NET] = DeltaP * (-v[2]*(-1)/2 - v[3]*(-1)/2 - v[1]*(1)/2 - v[4]*(1)/2);

w[NET] = DeltaP*((1/2)*v[2]+(1/2)*v[3]-(1/2)*v[1]-(1/2)*v[4])

(5)

eq14_2_2 := rhs(eq14_1_3) = rhs(eq14_2);

Delta*T[Sfg] = -(1/2)*v[2](-DeltaP)-(1/2)*v[3](-DeltaP)-(1/2)*v[1](DeltaP)-(1/2)*v[4](DeltaP)

(6)

eq14_2_3 := eq14_2_2 / DeltaP; # Q2

Delta*T[Sfg]/DeltaP = (-(1/2)*v[2](-DeltaP)-(1/2)*v[3](-DeltaP)-(1/2)*v[1](DeltaP)-(1/2)*v[4](DeltaP))/DeltaP

(7)

Desired2 := w[NET]/DeltaP =  (-v[2]*(-1)/2 - v[3]*(-1)/2 - v[1]*(1)/2 - v[4]*(1)/2);

w[NET]/DeltaP = (1/2)*v[2]+(1/2)*v[3]-(1/2)*v[1]-(1/2)*v[4]

(8)

 

Download Q20220110.mw

Thank you everyone!

I am trying to solve an ODE with nonlinear boundary conditions, it is a BVP. And the maple let me to specify an approximate initial solution. I just don't know how to define the initial solution. What format is the initial solution? I have tried the Help Document told me to, but I still can't figure it out. Please help me, thank you!

Hi. 

Just trying to replicate a calculation, I would expect close to absolute zero, but my units are out

Black_hole_temp.mw

Initial text in the uploaded worksheet describes an attempt to partially tile the Poincare disk and asks to be shown how a known complex transformation can be used to accomplish this.

 Poincare_tiling.mw

The worksheet below contains the desired hyperbolic action and asks for the specific transformation that performs it.

Hyperbolic_Transformation.mw

I have corrected the above worksheet so that the Poincare disk is now centred at [0,0].

I hope this helps you answer my question

Anyone can help me to convert matlab codes to maple, pls, this is my code p

Plotting of a nonlinear differential equation?

Every time I open Maple it has the invitation to Login in the top right-hand corner.  I would like to sign in but have had quite a bit of trouble doing that.  I have a user name and password with Maplesoft web store and the same for MaplePrimes.  Should either of these work to log in? 

Hi. I can't seem to get my Explore plot to work. Maple gives me a cryptic error message (IMHO).

Rectangle_within_circle_gen.mw

Rectangle_within_semicircle.mw

Hi..What I want should be self explanetary. Trying to Explore 2 plots on the one graph.

First 7 8 9 10 11 12 13 Last Page 9 of 56