## phrasing skynet...

yep the errors recieved using some packages are very very specific for maple, for example, the one i got today using the ODE package was profoundly helpful:

Error, (in ODEtools/info) unable to handle derivatives as {diff(1/(ln(X)-Psi(1-f(X))-Psi(f(X))), [`\$`(X, n-k[1]-k[2])]), diff(1/f(X), [`\$`(X, n-k[1]-k[2])]), diff(Psi(1-f(X)), [`\$`(X, k[2])]), diff(Psi(f(X)), [`\$`(X, k[2])]), diff(f(X), [`\$`(X, k[1])])} while solving w.r.t f(X)

## Integration problem in 2015 and 2015...

Hi,

1st post. I'm trying to integrate the following function:

h:=t->(2*t-1)*cos*sqrt(3*(2*t-1)^2+6)/(sqrt(3*(2*t-1)^2+6));

h:=t->(2*t-1)*cos*(sqrt(3*(2*t-1)^2+6))/(sqrt(3*(2*t-1)^2+6));

h:=t->(2*t-1)*(cos*(sqrt(3*(2*t-1)^2+6)))/(sqrt(3*(2*t-1)^2+6));

h:=t->((2*t-1)*(cos*(sqrt(3*(2*t-1)^2+6))))/(sqrt(3*(2*t-1)^2+6));

int(h(t),t); ** Integration command. I've also replaced the "h(t)" with the entire function.

I've tried the following:

1. Changed the "t" to "x" throughout function.

2. Added parens around sqrt portion.

3. Added parens to include "cos" and then added to include the beginning (2*t-1).

4. I've added brackets around the numerator but this just causes Maple to reprint the function with the inegration sign in front of the function.

5. I've also tried using the Integration tutor. It returns that maple is unable to calculate.

6. Repeat all the above in Maple 2015, same answer.

I always get cos(t^2-t).

The math book claims the answer is 1/6*sin*sqrt(3*(2*t-1)^2+6). When I perform the inegration on paper I get the same answer.

Any suggestions or corrections would be great.

Thank you,

Jay.

pls help review this code, its doesnt return a solution

restart;
Digits := 16;
M := .5; lambda := .5; Pr := .72; beta := 1; L[w] := 0; m := 1; R := 1; Ec := 1;
N := 7;
for j from 0 to N do J[j] := sum(f[k](t)*(diff(f[j-k](t), `\$`(t, 2))), k = 0 .. j) end do;
for i from 0 to N do K[i] := sum((diff(f[k](t), t))*(diff(f[i-k](t), t)), k = 0 .. i) end do;
for j from 0 to N do G[j] := sum(f[k](t)*(diff(theta[j-k](t), t)), k = 0 .. j) end do;
for j from 0 to N do H[j] := sum((diff(f[k](t), t))*theta[j-k](t), k = 0 .. j) end do;
for i from 0 to N do P[i] := sum((diff(f[k](t), t, t))*(diff(f[i-k](t), t)), k = 0 .. i) end do;
epsilon := 1; delta := 0;
f[0] := proc (t) options operator, arrow; L[w]+epsilon+delta*A*t+(1/2)*A*t^2 end proc;
1 2
t -> L[w] + epsilon + delta A t + - A t
2
theta[0] := proc (t) options operator, arrow; 1+B*t end proc;
t -> 1 + B t
NULL;
;
NULL;
NULL;
NULL;
NULL;
for i to N do f[i] := simplify(-((m+1)*(1/2))*(int(int(int(J[i-1], t = 0 .. eta), t = 0 .. eta), t = 0 .. eta))+m*(int(int(int(1-K[i-1], t = 0 .. eta), t = 0 .. eta), t = 0 .. eta))-M*(int(int(int(diff(f[i-1](t), t)-1, t = 0 .. eta), t = 0 .. eta), t = 0 .. eta))-lambda*(int(int(int(theta[i-1](t), t = 0 .. eta), t = 0 .. eta), t = 0 .. eta))); f[i] := unapply(f[i], eta); theta[i] := simplify(-3*Pr*R*(((m+1)*(1/2))*(int(int(G[i-1], t = 0 .. eta), t = 0 .. eta))-(2*m-1)*(int(int(H[i-1], t = 0 .. eta), t = 0 .. eta))+Ec*(int(int(P[i-1], t = 0 .. eta), t = 0 .. eta)))/(4+3*R)); theta[i] := unapply(theta[i], eta) end do;
NULL;
F(eta):=collect((&sum;)f[z](eta),eta):
Theta(eta):=collect((&sum;)theta[z](eta),eta):
with(numapprox);
for k from 2 to 5 do W[k] := pade(diff(F(eta), eta), eta, [k, k]); Q[k] := pade(Theta(eta), eta, [k, k]); SOLL1[k] := expand(coeff(numer(W[k]), eta^k)) = 1; SOLL2[k] := expand(coeff(numer(Q[k]), eta^k)) = 0; SOL[k] := solve({SOLL1[k], SOLL2[k]}, {A, B}); print([k] = SOL[k]) end do;
Warning, computation interrupted

## Datatype error (float[8])...

I'm sorry for asking too many similar technical questions, but I just can't help this.

I'm solving a system of differential equations with dsolve and getting this type of error:

Error, (in f) unable to store 'HFloat(0.10664489706950975)+HFloat(1.1891638418458722e-5)*sin^2-HFloat(1.6095871822513048e-6)*sin' when datatype=float[8]

I checked the dsolve syntax, checked that all the constants are defined, checked that the number of equations matches the number of unknown functions (and there is no misprints of them in the code). In brief, I checked all the stuff that I usually have mistakes in, and yet the error stands.

Here's the file: 1.mw

## cannot find the error in loop...

cannot find the error in loop

> restart; u[0] := (4/3)*c^2*cos((1/4)*x)^2; alpha := 2;

> iteration := 3;
> for k from 0 while k <= Iteration do u[s] := eval(u[k], t = xi); u[k+1] := simplify(u[k]-(int(diff(u[s], [`\$`(xi, alpha)])+diff(u[s]*u[s], x)+diff(u[s]*u[s], x, x, x), xi = 0 .. t))) end do;

## solve using assume option...

how can solve using assume option ?

 > restart:
 > F(z):=m*z^4-4*m*z^3+(3*m+3)*z^2-6*u;
 (1)
 > solve(F(z),z assuming -0.5
 >

## Computing the Sine and Cosine Funtion...

Hi,

When I type sin(pi/2) the result is sin(pi/2) (not "1.0)

What should I do to get "1.0" instead of replicating the sin(pi/2) ?!

I mean why the expression contating "pi" can not being simplified?

Is there any solution to this problem?

Thanks

## Iterated Functions...

how are iterated functions represented in maple? as in f(f(f(x))) is (x)  in conventional notation where by the reader knows it is refering to the iteration conducted 3 times on the argument x, but what does maple use to differentiate between iteration ,exponentiation and differentiation?

## why "end proc();" do not generate an error?...

when writing by error the following

restart;
f:=proc()
dsolve(diff(y(x),x)+y(x)=0,y(x));
end proc();

Maple did not complain and returned  f := y(x) = _C1*exp(-x)

Then I noticed I needed to change "end proc();" to "end proc;"

The question is, why did Maple not generate a syntax error? If "end proc();" is valid Maple code, then what does it mean? or Did Maple ignore it? what is the parsing steps used to make Maple generate the above output?

## Simple program does not work...

I have two sets

f:={1,2,3,4};

h:={1,2,4,5}

L=seq(i,i=1..4):

I want to program , if it is true that f[i] = h[i], then it prints f[i]. So the output should be {1,2}.

for i in L do
if evalb(f[i]=h[i]) then
print(f[i]);
end if;
end do;

I get no output. https://i.imgur.com/qA5hU3i.png

I tried changing the set f to list, f:= [1,2,3,4], still no output.

## How to solve this PDE system?...

bbb2.mw

 (1)

 (2)

 (3)

 (4)

 (5)

if former equations are not solvable , please help me for another way, in which at first two equation solve..in this way in equation [J and B] assume that q[311]=e[311]=0 and dsolve perform to find Φ and  ψ

after by finding Φ and  ψ is use for detemine w and u0

bbb2_2.mw

## Long Commands in Maple...

hi all,

How could I write long commands in Maple?

For instance: a long vector in Matlab could be written in this way:

A=[ 3, 4, 5, 6, 6, 45, 37...

5, 4, 67, 39, -967 ];

But what is that in Maple???

## Incorrect syntax...

Error, illegal use of an object as a name''

thanks

PLATE.mw