## Loop for composites...

I have a homework ask you to find the first string of (at least)10, 50, 100 consecutive composites. I have no idea how to use maple. HELP

all i can think of is

>ithprime(i+1) - ithprime(i) = 10

>print(i+1, i)

and combine it with some loop

i dont know how to set up a loop

need a lot of help

## Plot of certain function ...

Hello

I have an SEIR model.

Equation 5 is for disease death but I would like to plot the cumulative numbers of disease death which will be the integral of Equation 5. I added the integral inside odeplot but it is not working. Any idea  about  how to compute the integral ?

Maple code is attached

Thank you

code.mw

## How to plot Fourier transform?...

Hi,

I was wondering how to go about plotting a Fourier Tranform in Maple.

My assignment is to plot a simple harmonic equation as a Fourier transform, depicting amplitude against fequency.

I've been given: x'' + w^2 x = 0

And want to obtain both the f(x) = a0 sin(wt) + b0cos(wt) form, and a graph of the the amplitude (c^2 =a0^2 + b0^2) against frequency.

I know how to do this on paper but not in Maple, so any help with line commands and layout would be very much appreciated.

Thanks

## Bcount definitions in Maple ...

I need to complete the definition of bcount so that bcount(n) returns the total number
of odd coefficients 
n
k , 0 ≤ k ≤ n. For instance, the values of 
n
k for n = 6, with odd values highlighted, are:
1, 6, 15, 20, 15, 6, 1,

bcount:=
proc(n::TYPE)
description "Count odd binomial coefficients.";
---MORE STUFF HERE---
end proc; # bcount

Any help appreciated

## Change of the binomial definition ...

the binomial coefficient  n k  can be defined recursively as follows for all nonnegative integers n, k:

(n)  = {0,      k>0

(k)  = {1       k=0, k=n

{(n-1)+(n-1), otherwise.

(k-1)   (k)

I need to complete a deinition of binom so that m so that binom(n,k) returns  n k  for all n greater than 0, and k greater than or equal to 0 using the definition of the binomial above..Any help appreciated..

binom:=
proc(n::TYPE1,k::TYPE2)
description "Compute a binomial coefficient";
option remember;
---MORE STUFF HERE---
end proc; # binom

## Searching for a procedure in PDE...

I have the following two PDEs:

PDE := diff(u(x, t), t) = diff(u(x, t), x, x)+sin(x+t)-cos(x+t);

IBC:= D[1](u)(0,t)=-sin(t),
D[1](u)(1,t)=-sin(1+t),
u(x,0)=cos(x);

pds := pdsolve( PDE, [IBC], numeric, time = t, range = 0 .. 1,
spacestep = 1/32, timestep = 1/32,
errorest=true
)

PDE2 := diff(v(x, t), t) = diff(v(x, t), x, x);
IBC2:= D[1](v)(0,t)=0,
D[1](v)(1,t)=-0.000065*v(1, t)^4,
v(x,0)=1;

pds1 := pdsolve( PDE2, [IBC2], numeric, time = t, range = 0 .. 1,
spacestep = 1/32, timestep = 1/32,
errorest=true
);

Now, what I want to do with these two PDEs is the following:

For each h=timestep=spacestep  = 1/16 , 1/32 , 1/64 , 1/128 , 1/256

Calculate the error norm ||E||_h = sqrt(sum_{j=0}^{1/h} h* |u(j*h,tval)-v(j*h,tval)|^2)

where tval is some chosen point between 0 and 1 (this value is fixed for each spacestep chosen).

And then plot the graph of log ||E||_h vs. log h above.

What I don't know is how to extract each time the spacestep and its PDE's two solutions, does someone have a suggested script to use here?

## Convergence of Newton method...

let γ be the root

i have to apply taylor series on f(x) and then do some substitution like (helped by a member of Mapleprime)

restart;
taylor(f(x), x = gamma, 8);
f(x[n]) := subs([x-gamma = e[n], f(gamma) = 0, seq(((D@@k)(f))(gamma) = factorial(k)*c[k]*(D(f))(gamma), k = 1 .. 1000)], %)

then find the derivative of result from above output

i do

b := diff((x[n]), e[n])

basically i have to find the value of newton method which is

yn=xn-f(xn)/D(f)(xn)

here we substitute xn=γ and D(f)(xn)=b

and then want to apply f on yn

there are to problem which i face

1  f(xn)/D(f)(xn) is not in simplified form i-e O(e[n]^8) and O(e[n]^7) is appeared in numerator and denominator respectively. how we get the simplified result.

2 wht step should i do to find f(yn)

plx help me to do this

## Differential Equations...

Hey guys! Can anyone help me with solving one of these Differential Equations ?
Thanks.

!

## Patterns in Maple...

Explore the values of km digit(n,m) using km list for all m, 0 ≤ m ≤ 8.
Look at the output until you can make a conjecture that concerns the pattern
obtained for each fixed m, 0 ≤ m ≤ 8 using

km := proc (n::posint, m::nonnegint)

local k,

mySum := 0;

for k to n do

mySum := mySum+k^m

end do;

return mySum

end proc

using a list km list(m,6,20) when m is not a multiple of 4, and km list(m,6,50) when m is a multiple of 4.

any help appreciated..THank you

## Fibbonacci numbers in Maple...

Need to create a fibonacci defintiion using this form..Any help appreciated..thanks in advance

The Fibonacci numbers Fn are defined for all positive integers n as follows:

Fn = ( 1,                 n =1, 2 , )

(Fn−1 + Fn−2 , otherwise.)

Complete the definition of fib so that fib(n) returns Fn for all positive integers n. You must compute Fn using the below definition! A recursive proc is most natural.

fib:=
proc(n::posint)
description "Calculate fib(n), the n'th Fibonacci number.";
option remember; # important for efficiency!
---MORE STUFF HERE---
end proc; # fib

## Completing a loop in maple?...

I need to complete the definition of P km using a for loop so that km(n,m) returns n k=1 k m whenever n, m ∈ Z, n > 0, and m ≥ 0.( You must use a for loop in the variable k, with k ranging from 1 to n, to do this question in the manner requested.)

km is defined as

km:=
proc(n::TYPE1,m::TYPE2)
description "km(n,m) returns the sum of k^m as k ranges from 1 to n.";
---MORE STUFF HERE---
end proc; # km

Not sure where tostart..Any help appreciated...thank you

## problem in procedure...

hello all!

Pascal := proc (n::posint)

local x, y, i;

for i from 0 to n do print(coeffs(expand((x+y)^i)))

end do end proc;
Pascal(4);

1
1, 1
1, 2, 1
1, 3, 3, 1
1, 4, 6, 4, 1

How to create

1
1  1
1  2  1
1  3  3  1
1  4  6  4  1

## How to find such a matrix? ...

hello everybody!

I want to create a random symmetric matrix which have det=2. I just made it like this, no better than those ones. Thanks!

Doixung := proc (n)

local A, i, j; A := Matrix(n);

n := LinearAlgebra[Dimension](A);

for i to n do A[i, i] := RandomTools[Generate](integer(range = 1 .. 20))

end do;

for i to n do

for j to n do

while j < i do A[i, j] := RandomTools[Generate](integer(range = 1 .. 20)) end do;

while i < j do A[i, j] := A[j, i] end do

end do

end do;

print(A) end proc

## What is wrong with algorithm?...

Hello! I have written a algorithm. Can you help me find errors? thank you very much. sorry, my English is not very good!

LL:=proc(A::Matrix)
uses LA= LinearAlgebra;
local i, j, k, n:= LA:-RowDimension(A),
L:= Matrix(LA:-Dimensions(A));
L[1,1]:=sqrt(A[1,1]);
for j from 2 to n do
L[j,1]:=(A[j,1])/(L[1,1]);
end do;
for i from 2 to n-1 do