Good afternoon. How do I disable the numbering of _Z constants? Because
of this, you can't use the procedure in a loop
Is it possible to disable numbering or do something else?

Download help.mw

This does not work with Maple 13. Can I still do something like this just using the linear operator D?

g:=x->x^(1/3);

f:=x->convert(g(x),surd);

D(f)(x)???

I need the derivative D(f)!!

Thank you!!!

mapleatha

How do you print [0,infinity) in Maple 13 like
?

RealRange does not seem to work.

Thank you!

mapleatha

Hi all,

Look at my pretty plot.  It is defined by

x=sin(m*t);
y=sin(n*t);

where n and m are one digit positive integers.

You can modify my worksheet with different values of n and m.

pillow_curve.mw

pillow_curve.pdf

The name of the curve may be something like Curve of Lesotho.  I saw this first in one of my father's books.

Regards,
Matt

How do we replace D^i by diff(y(x),x$i) in did:=D^14+23*D^13+144*D^12
in Maple 13?

Thank you!

mapleatha

I have the expression:

This works (Ans. 144):

coeff(144*D^10,D,op(2,op(2,144*D^10)));

This works (Ans. 144):

coeff(op(3,did),D,op(2,op(2,op(3,did))));

Why doesn't this work?

eval(coeff(op(i,did),D,op(2,op(2,op(i,did)))),i=3);

Why doesn't this work?

subs(i=3,coeff(op(i,did),D,op(2,op(2,op(i,did)))));

I need those "generic" substituions for certain loops that I am making.

Thank you!

mapleatha

I would like to have Maple give me sin(2nPi) = 0 assuming that n is a positive integer. Is there a way to do it?

Thank you.
mapleatha.

I have this two expresions

e1 := (1/2)*P[psi]^2/(cos(`ϑ`)^2*Ix)

e2 := (1/2)*P[psi]^2/(cos(`ϑ`)^2*Ix)

simplify(e1-e2)=-(1/2)*(-P[psi]^2+P[psi]^2)/(cos(`ϑ`)^2*Ix)

but 

simplify(-P[psi]^2+P[psi]^2)

is zero 

why i dont obtain zero if i use simplify(e1-e2) ??

Hello Maple community and others,

It has been proven that every positive
rational number can be represented in 
Egyptian Fraction form

See wikipedia on Egyptian Fractions

We have the fact that the harmonic series diverges
Let Hn = 1 + 1/2 + 1/3 + ... + 1/n.

Then the limit as n goes to infinity of Hn is unbounded.

It seems these two facts go hand in hand.

Is there a procedure in Maple that will give
Egyptian Fraction representation of an arbitrary
rational number?

I made a worksheet with some examples.

egyptian_fractions.mw

egyptian_fractions.pdf

Regards,
Matt

Hello again,   I'm trying to write a procedure to multiply quaternions.   We know that they can be represented as a vector of length 4.   See Wikipedia.   My try  -

qaa=[8,4,6,2] and qab =[2,,4,6,8]
mult:=proc(a,b)

end proc;

maybe needs some looping or data from a table.  

Regards,

Matt

Hi all,

We want to find a curve fit for an integer sequence.

We have n such that n^2+n+17 is a prime number.

See oeis.org/A007635 and comments.

Use the Maple CurveFitting package.

I tried with(CurveFitting).

We do not know if this is best represented by a polynomial or exponential curve fit.

n2_and_n_and_17_in_OEIS_007635.mw

n2_and_n_and_17_in_OEIS_007635.pdf

Regards,

Matt

The low-level command is "RTABLE". I have used it a million times. I use it with Maple 13 to replace expressions by tables.
For example,

print(`Hello! `*RTABLE(1,x^2+y^2));

will print: Hello! x^2+y^2. However, the main reason I am using it is to avoid Maple messing up the order of things like sums,
products, etc. However, this command has disappeared. It does not exist in Maple 2020. So, I cannot run my programs at the university which now has Maple 2020. Anybody knows if this command can still be used in another form the same way?

Thank you!
mapleatha

Since I am a mathematician, I am wondering how Maple goes about solving an identity for 3 functions.
Let's say we have af1(t)+bf_2(t)+cf_3(t) = 0 for all t. How does maple actually find a triplet a,b,c that works for all real t?
It does with solve(identity( ),[a,b,c]). But what is the theory behind it?
We know, of course, a priori, that such a triplet exists.

Thank you!

mapleatha

Please refer to this for the definition(s):

http://www.mrob.com/pub/math/largenum-3.html#hyper

The hy(a,n,b) recursion turns  into the following Maple code:

Unfortunately this code depends on x and y being explicit numeric values (x,y \in N), otherwise the recursion crashes (if I ask for example H(2,x,y) or H(2, x, 2))

Is there any way to transform the code so that the final construct can be shown symbolically?

I don't see anything obvious, especially since if y is not a specific natural number the recursion will crash. Can we maybe force Maple to not evaluate it for natural number arguments and return the final construct as either a sum, product or tower of the symbols for x and y (i.e. symbols of the digits of x and y like a tower of 2's 3's, etc)?

I do remember something about putting primes around functions prevents premature evaluation, but in this case it doesn't do anything like I'd want. This definition is not primitive recursive (like that of the Ackerman function), so I don't expect it to be able to be called abstractly (H(2,x,y) or something else such), but maybe we can turn it into something that shows the structure of the final construct as symbols of the digits of x and y?

Thanks.

Yannis

PS: One can improve the situation a bit, by implementing the extended definition as:

hy := proc (n, x, y) if n = 0 then y+1 elif n = 1 then x+y else if y = 1 then x else if n = 2 then x*y elif n = 3 then x^y elif n = 4 then x^hy(4, x, y-1) else hy(n-1, x, hy(n, x, y-1)) end if end if end if end proc

(which can be called abstractly for n=0,1,2,3,4 (hy(n,x,m) for natural m), but for higher n it crashes similar to H, since the definition falls back to the previous if n>4.

There are some answers up here, but they are for given known functions.
I need to place parentheses around functions that are automatically created.
For example, the function $f(x)$ takes many polynomial values during the execution
of a procedure. For examplle, it takes the values, 2x-1, x^2+3x+2, x^3-2x-3, etc.
How do I automatically place parentheses around these polynomials?
Thank you!
mapleatha