## Warning, solution may have been lost...

Hi! when i'm trying to solve, i get the following warning: Warning, solutions may have been lost.

The equations i'm trying to solve are as the following:

>A=0.1;

> D=0.19;

> eqns:={y^1.5-9/8*B^0.5*y+3/4*x*y^0.5-3/4*(Pi/3)^0.5*[1+(1+3/4*(Pi/3)*(B*(1+x^2))^0.5)*x^2]/(1+x^2)^0.5=0, Pi/2-3*D=8/3*y^3+x*y^2+4*B^0.5*[1/3*B*y^1.5-2/45*B^2.5-3/2*y^2.5]-9/2*B*(1/3*B*y-3/40*B^2-3/4*y^2)-3*x*B^0.5*[1/3*B*y^0.5-1/7*B^1.5-1/2*y^1.5],B=A/(1+x^2)};

> vars:={x,y,B};

> solve(eqns,vars);

Warning, solutions may have been lost

What am i doing wrong?

Many thanks!

## Calling Part of Piecewise Function...

f:=piecewise(x>0,1+x,x=0,2,x<0,1+x^2)

in my work i must use some parts of this piecewise function.

But i don't know how can i call the part that i will use.

How can i do that ?

Thanks for help

## How do I solve this integration in Maple?...

Hai everyone.

I try to double integrate this generalized extreme distribution.

q[p] := 6.256: h := .8; t[c] := .45: S[di] := 0: k[v] := .32639: mu[v] := -0.1786e-1: sigma[v] := 2.1694: k[t] := .36132: mu[t] := .63543: sigma[t] := 3.1183:

int(exp(-(1+k[v]*(v-mu[v])/sigma[v])^(-1/k[v]))*(1+k[v]*(v-mu[v])/sigma[v])^(-1-1/k[v])*exp(-(1+k[t]*(t-mu[t])/sigma[t])^(-1/k[t]))*(1+k[t]*(t-mu[t])/sigma[t])^(-1-1/k[t])/(sigma[v]*sigma[t]), [v = q[p]/(2*h*t)+q[p]*t[c]/(2*h)+S[di] .. infinity, t = 0 .. infinity]);

however, I got an error, as follow:

Error, (in assuming) when calling '`root/fraction`'. Received: 'numeric exception: overflow'

Any recomendations and tips to solve this integration? or this integration may cannot solve?

Thank you.

## Pointplot with different colors...

I have 20 datapoints in two groups. I may name them as f[1],...,f[10];g[1],...,g[10]. f[1]:=[1.2,3.5] etc

I would like to plot these 20 points

(1) in one plot

(2) f[1]~f[10] in one color; g[1]~g[10] in another color.

I checked http://www.maplesoft.com/support/help/Maple/view.aspx?path=plots%2fpointplot

and did not get the point :(

Do you any suggestion what can I do to realize the aims (1) and (2)?

Thank you very much in advance!

Hi,

I tried to use generated random as following

***

for j from 1 to 5 do
c:=rand(0..1):
d:=c();
print(`random number`,c(),d);

if c()=1 then

print(`Y`)
else
print(`N`);
end if;
end do:

***

The output is

****

random number, 1, 0

Y

random number, 1, 1

Y

random number, 1, 1

N

random number, 1, 1

N

random number, 0, 0

N

****

Why the output numbers in one line are different? And Using "if" sentence seems do not correspond to the printed "c()" value..

Thank you very much in advance!

## unable to execute add...

Dear Sir,  I want to know why the procedure  appear the error : (in U1) unable to execute add.

My procedure:

restart:
>
> h0:=0.156;
> d:=0.32*h0;
> l:=1;
> h1:=h0-d;
> h2:=h0+d;
> h5:=evalf(2/3*h0);
> h7:=h0;
> s1:=evalf(2/3);
> s2:=evalf(2/3);
> g:=9.8;
> d1:=1;
> Term:=10;
> Num:=5:
> n:=1:
>
>
> for N from 1 to Num do
> k0:=evalf(0.5*Pi+2*(N-1)*Pi/(Num-1)):...

## How can I plot f(x,y)=(cos(x^2+y^2))^1/2 whithout ...

How can I plot f(x,y)=(cos(x^2+y^2))^1/2 whithout knowing the domain?

And then having Maple to find the domain and plot it?

Thanks.

## maple 10 changes + and - for C´s and K´s in Word 2...

Hi i´m writing a paper about math and i use maple 10 and M. Word 2007 for it, i started with a Laptop with Windows 7 and when i finished it, i open the archive in a desk computer having the same especifications  i notice that the images of ecuations were altered changing "+" and "-" for "C´s" and "K´s", i tried a lot of computers with others especifications and my problem still the same, i changed the format and other stuff but i can´t...

## NLPSolve. Funny but nasty problem....

Dear all,

I have encoutered a funny problem with Optimization package. I minimize some long stuff (lets call it A) and get an answer, e.g.

[.116553990209052046e-19, [n = 4.24568325257496060, rhocut = 1.66125593854788400, m = 2.00000021862965971, rho = .956914761577446150]]

then i just do

evalf(subs(n = 4.24568325257496060, rhocut = 1.66125593854788400, m = 2.00000021862965971, rho = .956914761577446150, A));

and i get

## Recursive function definition does not work with s...

Hi! Normally recursively defined functions work well, but if I use a sum inside, this happens:

> y:=n->sum(y(k),k=0..n-1);

n - 1
...

## "How do I solve partial differential equation in M...

so...here it is that equation:

du/dt   = d2u/dr2 +  du/r*dr  +  u  +  f(r,t);     r=(0,...,2]; t(0,...,1]

also we have conditions:

u(r,0)=0;

u(0,t)=t2;

u(2,t)=0

I need to find u(r,t) and to graph it

r and t are cylindric coordinates.

f(r,t) is some definite function.

## How can i solve this differential equation?...

dsolve command doesn't work :(

it's very important =\

y*(dy/dx) + 2b*y*|y| + x*k^2 = 0

## Extracting Data out of own type...

Hi there,

I have defined an own type MyType wich is internally just a list ['MyType', A, B] with let's say two lists A,B and the symbol 'MyType' as first element (to identify the type).

Now, if I define

X := MyType('MyType', A, B);

is there a possibility to extract A out of X by something like

X[2]

or even better X[1] (thus skipping the first one)? The only thing I know is op(2, X).

## mapple fraction simplification...

Dear folks,

In mapple programming while assigning a fraction to a variable...it directly simplifies it....

eg: x:=4/6 and it directly gives 2/3

can we make mapple not to simlify this fraction....

It is very important for me to find out....