Kitonum

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17 years, 203 days

MaplePrimes Activity


These are replies submitted by Kitonum

Give specific examples with inverse trigonometric functions, in which you have issues. Then we will try to help you to use Maple to solve them.

@vv  Thanks for the link. Still seems a little odd that when using  evalf  command for an inert sum, by default generalized formal summation used instead of an usual summation (as the limit of the partial sums).

@Kitonum   with a large number of lines. The arrow was made in Paint:

R := evalc(1/(1-x-I*y)):

R1 := op(1, R), coeff(R, I):

f := unapply([R1], x, y):

F := plottools[transform](f):

A := plot([seq([convert(<cos(1/8*Pi*i), -sin(1/8*Pi*i); sin(1/8*Pi*i), cos(1/8*Pi*i)> . <t, 0>, list)[], t = -.95 .. .95], i = 0 .. 15), seq([r*cos(t), r*sin(t), t = 0 .. 2*Pi], r = 0.1 .. 0.95, 0.085)], color = red, thickness = 0, view = [-1 .. 1, -1 .. 1], numpoints = 1000, view = [-3.5 .. 3.5, -3.5 .. 3.5]):

B := plots[display](F(A), view = [0 .. 7.5, -3.5 .. 3.5]):

plots[display](<A | B>, scaling = constrained, axes = box);

 

 

 

 

 

@Carl Love  Thank you for your helpful comment. I had never thought about the possibility of adjusting the thickness of the gridlines. Especially I like monochrome color with thin gridlines:

y := 0: z := 0:

plot3d(abs((2*(-exp(-t-x-z)+exp(t+x+z)))/(exp(-t-x-z)+tanh((1+I)*t+(1/2-1/2*I)*y+z)+exp(t+x+z))), x = -5 .. 5, t = -5 .. 5, color = khaki, thickness = 0, axes = normal, orientation = [15, 50], numpoints = 20000);

                        

 

 

@mskalsi  I do not know how to explain this effect.

@Vic  Maple does it automatically:

Example:

solve({x+y=0, x+y=1});

 

Nothing was printed.

@Abdoulaye  In this case, do a procedure with formal parameter .

@baharm31  You wrote "It is easy to do what you did when the horizontal and vertical axis are the same size."  It is not necessary.

Example:

plot(sin(x), x=-Pi/2..Pi/2, size=[157,100], tickmarks=[spacing(Pi/4),default]);  # Font by default, size=12

plot(sin(x), x=-Pi/2..Pi/2, size=[157,100], tickmarks=[spacing(Pi/4),default], font=[TIMES,ROMAN,8]);

                                                             

 

 

 

 

 

@acer  Thank you, very useful comment.

If we want also simplify the trig term then:

A:=y(x)=1/3/2^x+_C1/(3^x)^2 + cos(x)*sin(x):

combine(A, {power, trig}); 

                           y(x) = 1/3*2^(-x)+_C1*3^(-2*x)+1/2*sin(2*x)  

 

@Markiyan Hirnyk  You are not right. From Collins dictionary:

partial ['pɑːʃəl] 1) relating to only a part; not general or complete a partial eclipse 2) biased a partial judge 3) (postpositive; foll by to) having a particular liking (for) 4) botany a) constituting part of a larger structure a partial umbel b) used for only part of the life cycle of a plant a partial habitat c) (of a parasite) not exclusively parasitic 5) mathematics designating or relating to an operation in which only one of a set of independent variables is considered at a time 6) Also called: partial tone music , acoustics any of the component tones of a single musical sound, including both those that belong to the harmonic series of the sound and those that do not 7) mathematics a partial derivative

 

See the meaning 7)

I can confirm. I already wrote about this error here.

 

Maple 2016.1 also fails to your task:

restart:

with(Optimization):

LPSolve(2*x+5*y, {3*x-y = 1, x-y <= 5}, assume = {integer, nonnegative});

  Error, (in Optimization:-LPSolve) no feasible integer point found; use feasibilitytolerance option to adjust tolerance

 

Addition: my Maples 2015 and 2016 are 32-bit

@Carl Love  

If you write as you suggest, then:

1. The original issue does not indicate that the numbers must be positive.
2. You can lose also positive solutions, see

sols := [isolve(sum(2*(m+i-1)+1,i=1..n) = 16)]:

S:=select(type, sols, set(name = posint));

nops(S);

for s in S do

[seq(eval(2*m+1+2*(n-1),s[1]), n=1..eval(n,s[2]))] ;

od;

                           S := [{m = 3, n = 2}]

                                            1

                                         [7, 9]

 

The solution  [1,3,5,7]  is lost.

@iman  I checked your statement.

See

 

``

A := Matrix(2, 2, {(1, 1) = (d-3)/(d-2), (1, 2) = -b/d, (2, 1) = d/((d-2)*b), (2, 2) = 1})

Matrix([[(d-3)/(d-2), -b/d], [d/((d-2)*b), 1]])

(1)

``

w := (1/2)*(2*d-5+I*sqrt(4*d-9))/(d-2)

(1/2)*(2*d-5+I*(4*d-9)^(1/2))/(d-2)

(2)

Q := Vector([(d-2)*b/d, -1/2-I*sqrt(d-9/4)])

Vector[column]([[(d-2)*b/d], [-1/2-((1/2)*I)*(4*d-9)^(1/2)]])

(3)

simplify(A.Q-w*Q)

Vector[column]([[0], [0]])

(4)

``

Maple does not find this nontrivial solution.

Download 123456.mw


 Edited.

 

@Carl Love  I think the reason for the failure of OP is in using  vector  command instead of  Vector.

See:

X:=[seq(i^2, i=1..20)]:  # list 1

Y:=[seq(i^3, i=1..20)]:  # list 2

M:=vector(20, x->X[x]):

N:=vector(20, x->Y[x]):

plot(M,N); 

                      

 

 

 

Good morning  Alsu! I am very pleased to see the new user from Russia in this  forum. I live right next to you in the city of Penza.

Here are some tips to improve your codes:

1. To create simple animations to be more efficient use of  plots[animate]  command, in which the frames are generated automatically:

restart;

plots[animate](plot, [[x,y, y=-20..20], linestyle=2, color=red, thickness=4], x=-10..10, frames=60);

 

2. I do not understand why you use plots[implicitplot] command (instead of plot command) in your further examples  transformations of simple plots defined by explicit formulas. Using a list, you can create multiple plots in one coordinate system:

restart;

plot([sin(x), sin(3*x), sin(1/3*x)], x=-3*Pi..3*Pi, y=-1.4..1.4, color=[red,blue,green], linestyle=[2,1,1], thickness=[2,3,3], scaling=constrained, legend=[typeset("  График функции  ", y=sin(x)), typeset("   График функции  ", y=sin(3*x)), typeset("  График функции  ", y=sin(1/3*x))], legendstyle=[font=[times,roman,14]]);

 

 

 

3. To work with the objects, depending on the parameters,  Explore command is very helpful. See help for details on this command.

 

 

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