MaplePrimes Questions

I want to find real roots only.  Cannot we find a simplified formula for x in this case which gives only real roots? 

 

 

``

eq1 := a^2*x^3+Typesetting:-delayDotProduct(2*a*b-Typesetting:-delayDotProduct(a^2, e), x^2)+(-2*a*b*c^2-a*c+b^2)*x-c*b-d-b^2*e = 0:

``

# Formula

eq2 := A*x^3+B*x^2+C*x+E = 0:

``

NULL

a := .7438:

b := 15.12*z[1]+10.85*z[1]^2:

c := 18.92-17.76*z[2]:

d := -.9224:

e := 2.106-5.317*z[2]+2.87*z[2]^2:NULL

NULL

A := a^2:

B := -a^2*e+2*a*b:

C := -2*a*b*e^2-a*c+b^2:

E := -b^2*e-b*c-d:

``

eq2

.55323844*x^3+(-1.165120155+2.941568785*z[2]-1.587794323*z[2]^2+22.492512*z[1]+16.140460*z[1]^2)*x^2+(-1.4876*(15.12*z[1]+10.85*z[1]^2)*(2.106-5.317*z[2]+2.87*z[2]^2)^2-14.072696+13.209888*z[2]+(15.12*z[1]+10.85*z[1]^2)^2)*x-(15.12*z[1]+10.85*z[1]^2)^2*(2.106-5.317*z[2]+2.87*z[2]^2)-(15.12*z[1]+10.85*z[1]^2)*(18.92-17.76*z[2])+.9224 = 0

(1)

``

``# Putting z1 and z2 value

"(->)"

.55323844*x^3+14.11629660*x^2+83.26002702*x-3.52866181 = 0

(2)

 

"(->)"

[[x = 0.4208050385e-1], [x = -9.354079555], [x = -16.20375615]]

(3)

``

``

 

Download cubic.mw

Gentlemen

I know the following:{A>E,F>Z,F<P,Z>E,P<A} , all real Numbers

can I get maple to sort these in order largest to smallest.

[in this case:  A>P>F>Z>E ]

As the title, how to convert "sin(x)+cos(x)" and this kinds into "sqrt(2)*sin(x+pi/4)"?

Sum of two sine functions with the same cycle should can be converted into one sine function, with some amplitude gain and phase offset. 

 

While solving cubic formula, i got this warning in Maple.

Why D variable is protected? 

eq1 := A*x^3+B*x^2+C*x+D = 0

``

A := x^2:

B := 2*x*y-4*z^2:

C := -2*x*y*z+x^2-y*z:

D := 4*x^2-x*z

Error, attempting to assign to `D` which is protected.  Try declaring `local D`; see ?protect for details.

 

``

eq1

x^5+(2*x*y-4*z^2)*x^2+(-2*x*y*z+x^2-y*z)*x+D = 0

(1)

 

 

How can I join the points on this graph to look like the second graph below.

I'm trying to model a simple pendulum. I have arrived at this code which gives me an animation of a point swinging.

 

 

To analyse the pendulum I want to plot a graph of phi against time, but do not know how to take readings from my animation to plot a graph with.

Thanks.

Hi all,

I designed the animation and wanted to display it automatically in the embedded component. Instead of animation toolbar, is it possible to control animation through commands? How do I do that?

 Thanks.

Hello guys, I want maple to show me the time taken to execute the entire 500 loops shown in the code below. I read maple help and was able to come up with the code  (just part of the whole code).

st := time[real]():

for k from 1 to 500 do

  sol := LinearSolve(A, eval(b, [y[0]=y_init,z[0]=z_init])):
  y_init:=sol[9]:
  z_init:=sol[10]:
end do:


time[real]() - st;

my problem is that the time that shows varies/differs if i run it several times. I was expecting the same time interval of calculation. Am I doing something wrong?

how to solve this case which like sylvester

NullSpace(A*X+X*A) = B

find X?

 any things like 

A*X + X*A = NullSpace^-1(B)

 

if i assume Matrix([[x1,x2,x3],[x4,x5,x6],[x7,x8,x9]]);

find NullSpace(Matrix([[x1,x2,x3],[x4,x5,x6],[x7,x8,x9]]))

then from the equation of it, put all equations = 0, and then solve them

and then substitue value of B into the result, can it be said NullSpace^-1(B)?

Can we define/set a range in Maple. e.g 


I have the following equation:

y = 1.048 + 1.02*x + 6.118*(z-4.041*x^2) + 16.22*(z^2) +6.241* (x*z)

The value of z is within 0.001 - 0.543, y is from 1 - 12 and x is from 0.001 - 0.7

How should I define it in Maple, so while solving equations it read the values within the given range? 


x := (1+v/2*cos(u/2))*cos(u);
y := (1+v/2*cos(u/2))*sin(u);
z := v/2*sin(u/2);

I converted this comment into a question since it was unrelated to the question in which it was put.
That way also other MaplePrimes users can have a shot at this new question.
Preben Alsholm
 

Dear Preben Alsholm 

Hi;

Hope you to be healthy and have nice times,

I have another problem and if it doesn't consuming your valuable times, please guide me.

I have some Basis function,say W1(t),W2(t),W3(t),W4(t) which are orthonormal and i want to write a program that can approximate the integral of W(t)=[W1(t),W2(t),W3(t),W4(t)] again by Wi's, in other word
int(W(t')dt',t'=0..t)≈PW(t), where P is knows as integral operational matrix. the following is my attempt and unfortunately has no real solution!!!!

 

restart:
>              # Definition of 3th B-Spline
>
> piecewise(x>=0 and x<=1,1,0):
> h[1]:=unapply(%,x):
>
>             # Definition of 3th B-Spline
>
> h[2]:=simplify(int(h[1](x-t),t=0..1)):
> hh:=unapply(%,x):
>
>              #Definition of 3th B-Spline

int(hh(x-t),t=0..1): 
> simplify(%):
> N:=unapply(%,x):
>
> J:=1:     # Number of base function is 2^J+2
> phi:=linalg[matrix](2^J+2,1):
> for i from -2 to 2^J-1
> do
> N(2^J*x-i)*h[1](x): #for deleting out side of[0,1]
> simplify(%):
> phi[i+3,1]:=unapply(%,x):
> od:
>
> w[1]:=phi[1,1](x):
> w[1]/sqrt(int(w[1]^2,x=0..1)):
> W[1]:=unapply(%,x):     
>
> for i from 2 to 2^J+2
> do
> kk:=0:
> for j1 from 1 to i-1
> do
> aa[j1]:=int(phi[i,1](x)*w[j1],x=0..1):
> bb[j1]:=int(w[j1]^2,x=0..1):
> kk:=kk+aa[j1]/bb[j1]*w[j1]:
> od:
> w[i]:=simplify(phi[i,1](x)-kk):
> w[i]/sqrt(int(w[i]^2,x=0..1)):
> W[i]:=unapply(%,x):                 #Orthonormality process
>
>
> for j from 1 to 2^J+2 do
> for io from 1 to 2^J+2 do
> f[j]:=int(W[j](s),s=0..x);
> c[io][j]:=int(f[j](x)*W[io](x),x=0..1);
> od;
> od;

 

 

Best Wishes

I am new to Maple and I have difficulties simplifying expressions like the following: (exp(a+b)+exp(a+c))*exp(-a).

I would expect to see exp(b)+exp(c) but nothing happens when I use the simplify() function.

I googled but didn't find a solution.

Hi everyone,

 

At some point in my calculations, I want to do some simple manipulations wiht the use of the «clickable» features in M17.  For the moment, I can see directy how to do it by hand and I do it by copy-paste and use the mous to change it a little bit.  But I just cannot find a simple way to do it by simple click.

 

You will find in this attach question, the maipulations I want to do.  It is starting from equaiton (7).  Am I at the edge where it is simple by hand than with the features?

 Space_manipulation.mw

 

Thank you in advance.

--------------------------------------
Mario Lemelin
Maple 17.02 Ubuntu 13.10 - 64 bits
Maple 17 Win 7 - 64 bits messagerie : mario.lemelin@cgocable.ca téléphone :  (819) 376-0987
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