Does anyone understand this behavior? Why under some situations the exponential is not explicitly calculated by maple?

issue_matrix_exp.mw

I'm on linux x86_64, using Maple 2017.3

thanks.
 

Code:

restart:

H:=Matrix(4,4, 0):
H[2,3]:=a*exp(I*(b*x+phi)):
H[3,2]:=a*exp(-I*(b*x+phi)):
H;

LinearAlgebra:-MatrixExponential(-I*H); #result as I would expect

H2:=subs(a=0.1, b=0.3, phi=0.1, H); #substitute a few variables

LinearAlgebra:-MatrixExponential(-I*H2); #why does this not work?

H3:=subs(x=0.35, H2); #substitute numerical value for x as well

LinearAlgebra:-MatrixExponential(-I*H3); #now get a result

I wish to make a plot of the Bessel functions, J0(x) and J1(x) on the interval x=0 to 10.  

DEAR,

Working on my maple worksheet, suddenly the PC was shut down because of outage. Now I cant open my worksheet. When I open my file, Text format Choice window emerges without success in opennig the file withot regard which item selected. 

Could anybody help me open my worksheet.

Download MyWorkSheet.mw

Hi

Determine the extrema corresponds to a local minimum, maximum or
neither.

restart;
with(Optimization);

obj := 2*x^2+2*x*y+3*y^2;
  cts := [x+y = 2];
    Minimize(obj, cts);

    Maximize(obj, cts);

Maple display that there is no maximum, i d'ont understand why the maximum does not exist.

Many think

Hi, I'd like to use something to compare expressions, so I thought evalb or verify.

I'd like to evaluate things like the identity,

log_b(x ^y) = y ∙ log_b(x)

However using either I get:

> verify(2*log(x), log(x^2));

                             false
> evalb(2*log(x) = log(x^2));

                             false
now I thought maybe conditions might be different but as none are specified they should be the same in any domain. 

Not sure what is wrong or which comand is more suitable.

dear sir i want to plot a graph for different values of h(z) by applying do loop, hear is my codes

In K1 it should take first h(z)

In K2 it should take second h(z)

IN K3 it should take third h(z) 

restart:
h:=z->1-(delta2/2)*(1 + cos(2*(Pi/L1)*(z - d1 - L1))):
h:=z->1-(delta2/2)*(1 + cos(2*(Pi/L2)*(z - d2 - L2))):
h:=z->1+(delta2/2):
K1:=((4/h(z)^4)-(sin(alpha)/F)-h(z)^2+Nb*h(z)^4):
K2:=((4/h(z)^4)-(sin(alpha)/F)-h(z)^2+Nb*h(z)^4):
K3:=((4/h(z)^4)+(cos(alpha)/F)+h(z)^2+Nb*h(z)^4):
lambda1:=Int(K1,z=0..0.2):
lambda2:=Int(K2,z=0.2..0.4):
lambda3:=Int(K3,z=0.4..0.6):
lambda:=(lmbda1+lambda2+lambda3):
> 
F:=0.3:
L1:=0.2:
d1:=0.2:
d2:=0.2:
L2:=0.3:
alpha:=Pi/6:
plot( [seq(eval(lambda, Nb=j), j in [0.1,0.2,0.3])], delta2=0.02..0.1);
 

I want to stop the following loop when there is no more roots. how can i do this?

I mean the following Maple 2017.3 result

restart; with(Statistics):
X := RandomVariable(Geometric(1/3)):
Probability(sin(X) <= 1/2);
                            2839595/4782969

Mma 11.2 fails with it. It's unclear for me how Maple calculates the above result. Trying printlevel:=10:, I don't understand much. Also the result

solve({x >= 0, sin(x) <= 1/2}, [x], AllSolutions);
Warning, solutions may have been lost
  
[[x <= (1/6)*Pi, 0 <= x], [x <= 13*Pi*(1/6), 5*Pi*(1/6) <= x], [x <= 25*Pi*(1/6), 17*Pi*(1/6) <= x],
 [x = 29*Pi*(1/6)]]

does not encourage.

How can I find period of the following function with respect to p?
 

Thanks,

I am trying to recreate some plots from the research paper https://arxiv.org/pdf/0807.1597.pdf found on page 13 and 14, but so far I havn't really gotten anywhere. Would appreciate some help or hints so I can get further.

I can see my error here.Problem with Sigma(n^3). I sure i have done something stupid.

Download Sigma_problem.mw
 

Download Sigma_problem.mw

Hello everyone, I have 4 equations 4 unknowns I would like maple to compute it.  i might actually have a problem by  solve({eq1, eq2, eq3, eq4}, {Omega, alpha, beta, k}) command

alpha , beta , omega and k are unknows.

2.mw

I am using the Physics package for quantum mechanic.

Ket product are supposed to be noncommutative and the Simplify function
appears to ignore the propety.

I must be doing someting wrong.

Thank you for your help

LL

Can anyone understand why this is happening?

hello everybody, the below expression has 5 variabes: t,c,theta[1],lambda,a and i want to know in what ranges of variables the expression is positive. how can i do that?

y:=2*t*(((-(1/2)*theta[1]+1)*c^2+((1/2-(1/2)*theta[1])*t+a)*c-(1/2)*t^2)*lambda^3+((-3*theta[1]*(1/2)+2)*c^2+((7/2-4*theta[1])*t+2*a)*c+3*t*((-(1/2)*theta[1]+1/6)*t+a))*lambda^2+((-3*theta[1]*(1/2)+1)*c+(-2*theta[1]+1/2)*t+a)*(3*t+c)*lambda-(1/2)*(3*t+c)*(c*theta[1]+t*(3*theta[1]-1)))/((-2*t*lambda^2+(3*t+c)*lambda+c+3*t)*(lambda*c+3*t+c)*(lambda+1))

i use solve() to find these ranges but it takes to much time. is there any alternative solution?