## problem with higher order equations roots...

hey guys ,

i have problem to obtain roots for a higher order equation

## Solving equation with two reststricted variables...

How do I check if there are any solutions to this equation:
1/(u+v)^2+4*u*v-1=0
where both u and v are real numbers larger than 0.

## problem with solving inequality...

Dear all,

I am trying to solve this inequality:

0 < 2*b^2*(10*K*a+3*K*b-sqrt((K+(2*K*a+1)/b)^2-4*K/b)*b+5)

for a.

However, I get to the error below:

Error, (in testeq) invalid arguments
does anyone know which mistake I am making?!!

what is this testeq?!

## solve with units...

Hello,

how can I tell Maple that "u" has the dimension of volts?

## How do I solve non linear optimization problem and...

I want to maximize a total profit (TP) function which is dependent on five independent variables (E,W,T, theta, tp). All these five variables can have non negative values. The TP function is given below- ( first TP is directly copied from maple worksheet and than copied again as a picture for clear viewing).

TP = (p1*(Q-q)+p1*(1-theta)*(q-E)+s*E-c*Q-o-h*((1/6)*alpha*W^beta*a*p1^(-b)*tp^3/m-(1/2)*alpha*W^beta*a*p1^(-b)*tp^2+Q*tp)-(t1-tp)*h*((1/2*(-(2/3)*t1+m-(1/3)*tp))*W^beta*a*alpha*(t1-tp)*(-p1*(-1+theta))^(-b)+W*m)/m-(1/2)*h*(W+E)*(T-t1))/T-u*W

I am trying the maximize TP with respect to above five independent variables. I tried to solve  five equations ( representing first order partial derivative of TP with respect to each of the independent variables equated to zero) simultaneously by "solve" and "fsolve" command but both these commands fail to give any output. I have also tried three other commands in optimization package ( QPSolve, NLPSolve, Maximize) but all these three commands also doesn't give any output. I want to prove the concavity of TP function with respect to five independent variables, please guide how it can be done. ( I have computed the Hessian matrix but since five first order equations doesn't give output ( through fsolve command) so I am unable to compute Hessian at these first order optimiality condition solution.). The values of the paramters in the TP equation are -

[alpha = 50, beta = .7, c = 20, h = 4, m = .4, o = 10, p1 = 40, s = 10, u = 5, a = 15000, b = 2]

## System of linear equations...

I have to find the tangent lines to the circle x^2+y^2+6*x-8*y+25 = 1/16 which pass at the O(0;0)

So i make a general line y=m * x

Ho can i put m*x instead of y in the circle and calculate the delta of the equation that i get?

## Solve and RootOf(allvalues)...

I want to solve the problem described below. I tried using two methods as shown below, each method has been runing for days without solving it. I will really appreciate your help.

Det1 := (1/256)*(Aiso*(c+t)^2*(a^2+b^2)*(mu-1)*Pi^2-4*a^2*b^2*c*Gc)*(16*Aiso^2*Do^2*(c+t)^4*(a^2+b^2)^6*Pi^12+10*(a^2+b^2)^5*((c+t)^2*Aiso+4*Do)*Gc*(c+t)^2*c*a^2*Do*b^2*Aiso*Pi^10+(a^2+b^2)^4*((c+t)^2*Aiso+4*Do)^2*Gc^2*c^2*a^4*b^4*Pi^8-(1024/81)*a^6*Aiso^2*b^6*Tcr^2*(c+t)^4*(a^2+b^2)^2*Pi^4-(2560/81)*a^8*Aiso*b^8*c*Gc*Tcr^2*(c+t)^2*(a^2+b^2)*Pi^2-(1024/81)*a^10*b^10*c^2*Gc^2*Tcr^2)*(Aiso*(c+t)^2*(a^2+4*b^2)*(mu-1)*Pi^2-4*a^2*b^2*c*Gc)*(Aiso*(c+t)^2*(a^2+b^2)*(mu-1)*Pi^2-a^2*b^2*c*Gc)*(16*(c+t)^4*(a^2+(1/4)*b^2)^3*Do^2*(a^2+4*b^2)^3*Aiso^2*Pi^12+(10*(a^2+b^2))*((c+t)^2*Aiso+4*Do)*Gc*(c+t)^2*(a^2+(1/4)*b^2)^2*c*a^2*Do*(a^2+4*b^2)^2*b^2*Aiso*Pi^10+((c+t)^2*Aiso+4*Do)^2*Gc^2*(a^2+(1/4)*b^2)^2*c^2*a^4*(a^2+4*b^2)^2*b^4*Pi^8-(1024/81)*(c+t)^4*(a^2+(1/4)*b^2)*Tcr^2*a^6*(a^2+4*b^2)*b^6*Aiso^2*Pi^4-(2560/81)*a^8*Aiso*b^8*c*Gc*Tcr^2*(c+t)^2*(a^2+b^2)*Pi^2-(1024/81)*a^10*b^10*c^2*Gc^2*Tcr^2)*((mu-1)*(c+t)^2*(a^2+(1/4)*b^2)*Aiso*Pi^2-a^2*b^2*c*Gc)/(b^20*a^20*(c+t)^16) = 0;

# method 1;
EQN := RootOf(Det1, Tcr);

EQN_2 := allvalues(EQN);

# method 2;

EQN := solve(Det1, Tcr);

## Display 0.25 not .25...

Hello I have the following small piece of code.

XMLTools[Print](MathML[Export]('sin(theta)'=0.25));

which exports sin(theta)=.25, how do I force the 0 to display.

Also

why does the following fail:

sol:=solve([cot(x)=2,x>=0,x<2*Pi],x,AllSolutions, Explicit);

## likely quick and esy...

How do I get a system solve to dispaly an ordered triple and not {x=ans, y=ans, z=ans}

for instance

sys := { z = 4, x+y= 10, x-y = 5 };
L:=solve(sys, {x,y,z} );

displays

{x=7.5, y=2.5, z=4}

I want

{7.5,2.5,4}

## List solutions to Solve command without variable...

Hi All

I have the following line of code in Maple:

solve([sin(t), 0 < t, t < 6.28], t, allsolutions, explicit)

it produces: "{t = Pi}, {t = 2*Pi}, {t = 3*Pi}, {t = 4*Pi}, {t = 5*Pi}, {t = 6*Pi}, {t = 7*Pi}"

How do I get it to simply produce: "{Pi,2*Pi,2*Pi,3*Pi,4*Pi,5*Pi,6*Pi,7*Pi}

as having the variable listed is redundant and annoying when you want to go on and extract the 3rd solution (number only) form the list.

## solve function doesn't work !...

hello,

I am trying to solve a set of equations using solve but it didn't get me any answer !

> eq1 := x[1]-x[2] = 0;
> eq2 := -x[1]+2*x[2]-x[3] = 0;
> eq3 := -x[2]+2*x[3]-x[4] = 0;
> eq4 := -x[3]+x[4]-t = 0;
> solve({eq1, eq2, eq3, eq4}, {x[1], x[2], x[3], x[4]});

there is no error massage or anything.

any help?

thank you,

Mahdi

## how i can solve following equation?...

hi--how i can solve following equation?

thanks

Eq.mw

Maple Worksheet - Error

Failed to load the worksheet /maplenet/convert/Eq.mw .

## Bug in Maple solve?...

When I use Maple solve on functions that involves exp, ln to decide the maxima, minima points by solving derivative equals zero, it only returns the first point, not the second point.

Which by definition it shall return two points, one at 2.030837315, the other around 6.7.

See the Maple code and exported PDF attached.

Maple_Solve_MinMaxma.mw

Maple_Solve_MinMaxma.pdf

## solve a system of equation numericlly ...

i want to solve the system of equation ( 1 )  , (2)  ,  (3)   under the assumation that x , y have the CDF in (4)  ,  (5)

 >
 (1)
 >
 (2)
 >
 (3)
 >
 (4)
 >
 (5)
 >
 >