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## How can i use fracdiff commute for fractional PDEs...

Hi everybody, I want to find

the second-order derivative according to alpha. Since the computer could not calculate in this way, I took the derivative twice in a row.

assume(alpha <= 1)

then output is

again using the fracdiff

then output is

but I want to see

after the last command. Should alpha be defined specifically for this?

## something wrong with a function in a procedure...

Hello!

I have a difficulty with a function used in procedure. The procedure uses a multivariable function and if the specific choice of the function is not made the procedure seems to give proper result, but In case I make a specific choice of the function and then try use this procedure gives me incorrect result.

To be more exact I use Physics package (there is a need to calcute combinations of covariant derivates ). The calculations are performed in a curved space with a defined metric.

So here is the procedure:

SD2 := proc (psi) SumOverRepeatedIndices(g_[`~kappa`, `~lambda`]*(d_[kappa](d_[lambda](psi(X)))-Christoffel[`~sigma`, kappa, lambda]*d_[sigma](psi(X))))^2-SumOverRepeatedIndices(g_[`~kappa`, `~rho`]*(d_[kappa](d_[lambda](psi(X)))-Christoffel[`~sigma`, kappa, lambda]*d_[sigma](psi(X)))*g_[`~lambda`, `~tau`]*(d_[rho](d_[tau](psi(X)))-Christoffel[`~gamma`, rho, tau]*d_[gamma](psi(X)))) end proc;

If I turn to the procedure :

SD2(psi);

the result is  correct.

But  then I specify a psi function:

psi:=(t,r,x,y,z)->chi(r)+q*t;(here q is supposed to be a constant)

and turn to the procedure once again:

SD2(psi);

It gives me a wrong result.

I don't know what is the reason.

Thank you.

## Pythagorean Triples Ternary Tree

Maple 18

I make a maple worksheet for generating Pythagorean Triples Ternary Tree :

Around 10,000 records in the matrix currently !

You can set your desire size or export the Matrix as text ...

But yet ! I wish to understand from you better techniques If you have some suggestion ?

the mapleprimes Don't load my worksheet for preview so i put a screenshot !

Pythagoras_ternary.mw

Pythagoras_ternary_data.mw

Pythagoras_ternary_maple.mw

## How to plot the excel data...

Dear maple users,

Greeting for the day.

I have some data in an excel file. How to plot the excel data in contours with labels.

Also, how to show the x-axis range =-1.5..1.5 and y-axis range = -0.5..1 with the contour sequence -2..2.

XLdat.xlsx

Please see the figure for the model plot.

## Can this equation has four integer solutions?...

Can this equation has four integer solutions?
I am consider the equation a^2*x^2/(x-a)^2+x^2 = m/n and trying to find the integer numbers a, m, n so that the given equation has integer solutions?

Four_integer_solutions.mw

## How can i plot?...

Hi everyone how can I plot like a graphic?

## Phase portrait of fractional differential equation...

How to plot the phase portrait of the system of fractional DEs?

0< nu<1

## How to plot complex values?...

How to plot Complex vales in 2D?

Z be complex.

rho := 1/4; mu := 1/4; E := sum(Z^k/GAMMA(k*rho+mu), k = 0 .. 5)

## How to plot integral equation?...

How to solve and plot the integral equation?
b.mw

## Finding initial conditions exactly when the curve ...

Is it possible to solve DE without initial conditions
(1/24)*exp(-8)-(1/12)*exp(-5)+(1/24)*exp(-2)-(1/24)*exp(-10)+(1/24)*exp(-9)+(1/24)*exp(-1)+diff(f(x), x, x, x, x, x)+d*(diff(f(x), x))+e*f(x)+a*(diff(f(x), x, x, x, x))+b*(diff(f(x), x, x, x))+c*(diff(f(x), x, x))-1/24

where, a, b, c, d, and e are constant coefficients.....

## Differential equation of order 5 with ploting...

How to solve and plot DE?

eq1 := diff(f(x), `\$`(x, 5))+2*(diff(f(x), `\$`(x, 4)))+diff(f(x), `\$`(x, 3))+diff(f(x), `\$`(x, 2))+2*(diff(f(x), `\$`(x, 1)))+3*f(x) = g(x)

## How to solve Boundary value problem in set of eq...

System of equations with boundary conditions are moving?

Also, find the values of unknown variables?

## How to obtain a solution using pdsolve...

Dear maple users

Greetings.

In this code, I am solving the PDEs via perturbation method.

There is some mistake in the boundary condition and pdsolve.

Kindly help me that to get the solution for this PDE via perturbation method.