## Drawing of circles...

I can not spawn draw the circles C3 and C4

restart;
with(plots):
with(geometry):
_EnvHorizontalName := x:
_EnvVerticalName := y:
R := 7:
point(A, [0, R]):
line(L1, y = sqrt(3)*x + R):
line(L2, y = -sqrt(3)*x + R):
line(L3, y = R/3):
intersection(B, L1, L3):
intersection(C, L2, L3):
detail(C):
triangle(ABC, [A, B, C]):
circle(C1, [point(P1, [0, 0]), R]):
circle(C2, [point(P2, [0, R/3 + (2*R)/9]), (2*R)/9]):
detail(C2):
center(C2), coordinates(center(C2)):
reflection(P3, P2, C):
detail(P3):
reflection(C3, C2, C);
detail(C3):
Error, (in geometry:-reflection) unable to compute coeff
Error, (in geometry:-detail) unknown object:  C3
circle(C3, [point(P3*[(28*sqrt(3))/9, 7/9]), (2*R)/9]):
Error, (in geometry:-point) wrong number of arguments
reflection(C4, C2, B);
detail(C4);
Error, (in geometry:-reflection) unable to compute coeff
Error, (in geometry:-detail) unknown object:  C4
circle(C3*[point(P3, [(28*sqrt(3))/9, 7/9]), (2*R)/9]);
Error, (in geometry:-circle) wrong number of arguments

draw([L1(color = blue),
ABC(color = red, transparency = 0.5, filled = true),
L2(color = blue), L3(color = blue),
C1(color = blue, thickness = 3), C1(color = yellow, transparency = 0.8, filled = true), C2(color = blue, filled = true)],
axes = normal,
view = [-R .. R, -R .. R],
scaling = constrained);
Why these error messages. Thank you veru much.

## difficulty wirth rotation...

fig([L1(color = blue), L2(color = blue), L3(color = green), C1(color = black), C2(color = black), C3(color = orange), C4(color = orange)]);
point(oo, [0, 0]);
oo

rotation(fig1, fig, oo, Pi/2, 'counterclockwise');
Error, (in geometry:-rotation) wrong type of arguments why thos error ? Thank you;

## how to reduce evaluating time...

What should I do to reduce evaluating time?

 > restart;
 > with(plots):
 >
 > F:=kappa->kappa;
 (1)
 > f:=(alpha,delta)->exp(-abs(F(kappa))^2*(1+delta^2)/2-abs(F(kappa))*alpha)/abs(F(kappa));
 (2)
 > L:=(alpha,delta,Lambda)->(lambda^2*exp(-alpha^2/2)/4)*(Int(f(alpha,delta),kappa= -infinity..-Lambda)+Int(f(alpha,delta),kappa= Lambda..infinity));
 (3)
 > evalf(L(4,1,0.001));
 (4)
 > g:=(beta,delta)->exp(-I*kappa*beta-abs(F(kappa))^2*(1+delta^2)/2)/abs(F(kappa));
 (5)
 > E:=(omega,gamma)->exp(I*omega*gamma)*(1-erf((gamma+I*omega)/sqrt(2)));
 (6)
 > J:=(alpha,delta,Lambda,beta,gamma)->(lambda^2*exp(-alpha^2/2)/8)*abs(Int(g(beta,delta)*(E(abs(F(kappa)),gamma)+E(abs(F(kappa)),-gamma)),kappa=-infinity..-Lambda)+Int(g(beta,delta)*(E(abs(F(kappa)),gamma)+E(abs(F(kappa)),-gamma)),kappa=Lambda..infinity));
 (7)
 > #evalf(J(4,1,0.001,8,3));
 > N := (beta,alpha)-> (J(alpha,1,0.001,beta,3)-L(alpha,1,0.001))/\lambda^2;
 (8)
 >
 >
 >
 >
 >
 >
 > contourplot(evalf(N(beta,alpha)), beta=0..10,alpha=0..10,grid=[25,25]);
 >
 >
 >

## How to plot two functions on different domain in t...

I have the function: f(x)= sqrt(x) for x>=0; f(x)=1/x for x<0 and I would like to plot the function.

How exactly to implement this?

## difficulties with textplot and polygonplot...

restart;
with(plots): with(geometry):
_EnvHorizontalName := 'x':
_EnvVerticalName := 'y':
a := 7:
point(E, 0, a*sqrt(3)/2):
point(B, -a/2, 0):
point(C, a/2, 0):
point(o, 0, a*sqrt(3)/6):
point(A, 0, a/2):
point(H, 0, 0):
R := (3-sqrt(3))*sqrt(2)*a/12:
point(J, 0, a*sqrt(3)/6 - R):
triangle(Tr1, [E, B, C]):
triangle(Tr2, [A, B, C]):
StretchRotation(E1, E, B, Pi/4, clockwise, sqrt(2)/2);
coordinates(E1);
StretchRotation(E2, E, C, Pi/4, counterclockwise, sqrt(2)/2);
coordinates(E2);
triangle(Tr3, [E, B, E1]);
triangle(Tr4, [E, C, E2]);
triangle(Tr5, [B, C, J]);
circle(cir, [point(P1,[0,a*sqrt(3)/6]), R]):
poly := Matrix([[0, a*sqrt(3)/2], [-7/4 + (7*sqrt(3))/4, -7/4 + (7*sqrt(3))/4], [0, a/2], [7/4 - (7*sqrt(3))/4, -7/4 + (7*sqrt(3))/4]], datatype = float);
pol1 := polygonplot(poly, colour = "Magenta", transparency = 0.7, gridlines);
tex := textplot([0.2, a*sqrt(3)/2, "zE"], 'align' = {'above', 'right'});
draw([Tr1(color = cyan),
Tr3(color = green),
tex,
cir(color=blue),
Tr2(color = red),
Tr4(color = grey),
Tr1(color=blue)],'view' = [-5 .. 5, 0 .. 7],
axes = normal, scaling = constrained,size=[800,800]);
Error, (in geometry:-draw) the option must be of type equation or name
line(L1, [B, o]);
Equation(L1);
line(L1, -(7*x*sqrt(3))/6 + (7*y)/2 - (49*sqrt(3))/12 = 0);
reflection(J1, J, L1);
triangle(Tr6, [B, J1, E]);
line(L2, [C, o]);
Equation(L2);
line(L2, -(7*x*sqrt(3))/6 - (7*y)/2 + (49*sqrt(3))/12 = 0);
reflection(J3, J, L2);
triangle(Tr7, [C, J3, E]);
triangle(T1, [E, J1, A]);
triangle(T2, [E, C, E2]);
triangle(T3, [B, H, J]);
triangle(T4, [C, H, J]);

draw([cir(color = orange, filled = true, transparency = 0.1), pol1, Tr6(color = blue, filled = true, transparency = 0.2), Tr5(color = blue, filled = true, transparency = 0.2), Tr7(color = blue, filled = true, transparency = 0.2), T1(color = green, filled = true, transparency = 0.2), T2(color = green, filled = true, transparency = 0.2), T3(color = green, filled = true, transparency = 0.2), T4(color = green, filled = true, transparency = 0.2)], axes = none, scaling = constrained);
Error, (in geometry:-draw) the option must be of type equation or name
NULL;
NULL;

Why these errors messages ? Thank you.

## I want the numerical values of the partial derivat...

 > restart:
 >
 > N:=10
 (1)
 > PDE:=diff(u(y, t), t) = diff(u(y, t), y, y)
 (2)
 >
 > ICBC:= {u(y,0) = 0, u(0,t) = cos(t), u(N, t) = 0};
 (3)
 >
 > sol1:=pdsolve(PDE,ICBC,numeric,spacestep=0.025,timestep=0.00001):
 > u_at_1 := sol1:-value(u(y,t), t=0.1);
 > u_at_1(0);
 (4)

## Degrees package and working with RPMs...

Hello im an amateur using maple for my hidraulics machines course at engineering school. Does anyone know how to use the degrees package on maple 2021, i called it out by using the short form. with(Degrees): and then try to use sind but it doesnt recognice the command.

Also when using RPMs the units that should be giving me m/s appear as m2/m*s(radious). I know that the software recognice it as angular speed but is there anyway to eliminate the (radious) so i can work with the speed as lineal?

## ellipse in a rectangle...

with(geometry):
_EnvHorizontalName := x:
_EnvVerticalName := y:
a := 7:
b := a*(1/2 + 1/6*sqrt(45 - 24*sqrt(3)))^2:
r := b*sqrt(b)/(sqrt(a + b) + sqrt(a)):
point(A, -a, b): point(B, -a, -b):
point(C, a, -c): point(F, a, b):
Sq := square(Sq, [A, B, C, F]):
circle(C1, [point(P1, [r, 0]), r]):
circle(C2, [point(P2, [(1 + sqrt(3))*r, r]), r]):
circle(C3, [point(P3, [(1 + sqrt(3))*r, -r]), r]):
ellipse(E, x^2/a^2 + y^2/b^2 = 1, [x, y]):
solve({Equation(C1), x^2/a^2 + y^2/b^2 = 1}, {x, y}):
point(T, [5.349255162, 2.829908743]):
IsOnCircle(T, C1);
draw([E(color = cyan), C1(color = yellow, filled = true), T(symbol = solidcircle, symbolsize = 20, color = red), Sq, C2(color = red), C3(color = red),Sq(color=blue)], axes = normal, view = [-a .. a, -b .. b], scaling = constrained);
square: (196+(7*(1/2+(1/6)*(45-24*3^(1/2))^(1/2))^2+c)^2)^(1/2)-(196+196*(1/2+(1/6)*(45-24*3^(1/2))^(1/2))^4)^(1/2) = 0
square: (7/2)*(1/2+(1/6)*(45-24*3^(1/2))^(1/2))^2-(1/2)*c = 0
Error, (in geometry:-square) not enough information to define a square
false

Error, (in geometry:-draw) cannot determine the vertices for drawing .Why all these errors ? Thank you.

## inner bisector equation...

EqBIS := proc(P, U, V)
local a, eq1, M1, t, PU, PV, bissec1;
a := (P - U)/LinearAlgebra:-Norm(P - U, 2) + (P - V)/LinearAlgebra:-Norm(P - V, 2);
M1 := P + a*t;
eq1 := op(eliminate({x = M1[1], y = M1[2]}, t));
RETURN(op(eq1[2])); end proc;
EqBIS*([4, 5], [11, 7/3], [11, 5]);
why such a procedure gives no result Thabk you.

## Error, MapleSim does not evaluate to a module...

I have maplesim installed and I get the error "Error, MapleSim does not evaluate to a module" when I run A:=MapleSim:-LinkModel(); in a Maple worksheet.

Does anyone know how to solve this error?

## Plot inequality system...

Hi guys,

I know how to plot inequality system through using with(plots) and inequal term. however, I couldn't plot following system of inqulity equations:

alpha <= 0.0002500000000*(-18000.*m^2 + 47271.*m + 39514. + sqrt(3.24000000*10^8*m^4 - 1.701756000*10^9*m^3 - 4.266980559*10^9*m^2 - 3.036299412*10^9*m - 6.95987804*10^8))/(9.*m^2 + 12.*m + 4.), 0.00005000000000*(-90000.*m^2 + 237237.*m + 198158. + sqrt(8.100000000*10^9*m^4 - 4.270266000*10^10*m^3 - 1.069976858*10^11*m^2 - 7.612670111*10^10*m - 1.744924704*10^10))/(9.*m^2 + 12.*m + 4.) <= alpha, -0.6666666667 < m, m < -0.6665522013

please let me know how we can plot it.

with best

## Why can't Maple solve the below code for some par...

Hello everybody.

I wrote the attached code. this code gives a good result when "H" parameter is equal to 0.5. Even in this condition if I change other parameters, I can get a true result as well. But when I change "H" parameter to 0.6,0.7,0.8 or 0.9 the code can't be executed anymore and I can't get a result.

based on the paper, for H=0.6,0.7,0.8 or 0.9. we have a result.

what's the problem?

1.mw

## Equation of an ellpise after rotation...

restart:local D:
with(plots):
with(plottools):

a := 7;
b := a/2;
NULL;

r := b/2;
c := 2*sqrt(10)*r;
A := [c/2, c/2];
B := [c/2, -1/2*c];
C := [-c/2, (-c)/2];
D := [-c/2, c/2];
f := (x, y) -> x^2/a^2 + y^2/b^2 = 1;
Ell1 := rotate(implicitplot(f(x, y), x = -9 .. 9, y = -6 .. 6, color = blue), Pi/4);

g := (x, y) -> x^2/b^2 + y^2/a^2 = 1;
Ell2 := rotate(implicitplot(g(x, y), x = -10 .. 10, y = -10 .. 10, color = blue), Pi/4);

quadri := plot([A, B, C, D, A], x = -6 .. 6, y = -6 .. 6, filled = true, color = red, transparency = 0.7);
Cir1 := disk([c/2 - r, -c/2 + r], r, color = blue);
Cir2 := disk([-c/2 + r, -c/2 + r], r, color = blue);
Cir3 := disk([-c/2 + r, c/2 - r], r, color = blue);
Cir4 := disk([c/2 - r, c/2 - r], r, color = blue);
display([quadri, Ell1, Ell2, Cir1, Cir2, Cir3, Cir4], scaling = constrained, axes = normal);
how to find the equations of ellipses in order to fit them to discs and whiten the interior of ellipses ? Thank you.

## Difficultu with pointplot...

restart;
with(LinearAlgebra);
with(plots);
NULL;

EqBIS := proc(P, U, V) local a, eq1, M1, t, PU, PV, bissec1; a := (P - U)/LinearAlgebra:-Norm(P - U, 2) + (P - V)/LinearAlgebra:-Norm(P - V, 2); M1 := P + a*t; eq1 := op(eliminate({x = M1[1], y = M1[2]}, t)); RETURN(op(eq1[2])); end proc;
NULL;
A := <4, 8>;
B := <4, 2>;
C := <1, 4>;
EqBIS(A, B, C);
NULL;

Cen := proc(M, N, R) local eq1, eq2, sol; eq1 := EqBIS(M, N, R) = 0; eq2 := EqBIS(N, M, R) = 0; sol := simplify(solve({eq1, eq2}, {x, y})); RETURN([subs(sol, x), subs(sol, y)]); end proc;
Cen(A,B,C):

CircleParm := t -> [(-t^2 + 1)/(t^2 + 1), 2*t/(t^2 + 1)];
P1 := Transpose(convert(CircleParm(1/4), Vector));

P2 := Transpose(convert(CircleParm(5), Vector));
P3 := Transpose(convert(CircleParm(-1/10), Vector));
P4 := Transpose(convert(CircleParm(-3/2), Vector));

C1 := Transpose(convert(Cen(P1, P2, P3), Vector));
Pts := [P1, P2, P3, P4, C1];

display(implicitplot([x^2 + y^2 - 1], x = -2 .. 2, y = -4 .. 2, colour = [blue], scaling = constrained), pointplot(Pts, symbolsize = 16));
Error, (in plots:-pointplot) incorrect number of coordinates in points data
NULL;Why this error. Thank you.

## What is generating the R[0] term, and how do I rem...

I'm using Maple 2021, and my Euler-Lagrange equation is coming out with a R[0] term that should not be there. I want to know what is causing this error and how I can fix it.

Lagrangian

 (1.1)

Time Equation

 (2.1)