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August 19 2014 iman 10

Hi i have trouble with this equation to solve with maple please help me

with boundary condition :


how i solve above equation with maple?( there is function to solve this equation in maple ?

email :

Dear people in Maple Primes,


I have a question about how to solve a system of equations.

In the following equation, I want to eliminate D(a).

x := D(a*b*c = 3*d); 
y := D(a^2*b^3*c = 3*a);


For this purpose,

a code of 

d_a := isolate(x, D(a));

eval(y, d_a);

works well. But, for me, this code is a little laborious.

Is there any better way than the above way?


Thanks in advance.


taro yamada




   here are  equations like this

 sol := [abs(r)^2+abs(t)^2 = 1, r*conjugate(t)+t*conjugate(r), abs(r) = abs(t)]

when i solve this equations using command solve,the result  is none. and i used r=x+I*y,t=u+I*v in the equations,

sol:=[u^2+v^2+x^2+y^2 = 1, 2*u*x+2*v*y, sqrt(x^2+y^2) = sqrt(u^2+v^2)]

i still can't get a result.why,can you help me.



I am a problem with solve differential equation, please help me: THANKS 

g := (y^2-1)^2; I4 := int(g^4, y = -1 .. 1); I5 := 2*(int(g^3*(diff(g, y, y)), y = -1 .. 1)); I6 := int(g^3*(diff(g, y, y, y, y)), y = -1 .. 1); with(Student[Calculus1]); I10 := ApproximateInt(6/(1-f(x)*g)^2, y = -1 .. 1, method = simpson);

dsys3 := {I4*f(x)^2*(diff(f(x), x, x, x, x))+I5*f(x)^2*(diff(f(x), x, x))+I6*f(x)^3 = I10, f(-1) = 0, f(1) = 0, ((D@@1)(f))(-1) = 0, ((D@@1)(f))(1) = 0};

dsol5 := dsolve(dsys3, numeric, output = array([0.]));

              Error, (in dsolve/numeric/bvp) system is singular at left endpoint, use midpoint method instead

****************FORMAT TWO ********************************************************

g := (y^2-1)^2; I4 := int(g^4, y = -1 .. 1); I5 := 2*(int(g^3*(diff(g, y, y)), y = -1 .. 1)); I6 := int(g^3*(diff(g, y, y, y, y)), y = -1 .. 1); with(Student[Calculus1]); I10 := ApproximateInt(6/(1-f(x)*g)^2, y = -1 .. 1, method = simpson);
dsys3 := {I4*f(x)^2*(diff(f(x), x, x, x, x))+I5*f(x)^2*(diff(f(x), x, x))+I6*f(x)^3 = I10, f(-1) = 0, f(1) = 0, ((D@@1)(f))(-1) = 0, ((D@@1)(f))(1) = 0};

dsol5 := dsolve(dsys3, method = bvp[midrich], output = array([0.]));
                                   Error, (in dsolve) too many levels of recursion





Hi all


I am having a very complicated equation that has the form of 



Of course, the actual equation is more complicate than above. It is just an example. I want to solve the equation in terms of x. And I know that both x and y are real, and they are positive (greater than 0). My question is, how should I specify this when solving the equation?



PS: I try to run the program to the solve the equation (without specifying that they are real and positive), and at the output, it gave me something like:

"RootOf(y^2+2y+.......)".   What is that "RootOf" means? Square-root or what?

******************************************where d1 to d45 -kappa and chi are constant**********

dsys4 := {d1*h1(theta)+d2*(diff(h1(theta), theta, theta))+d3*(diff(h2(theta), theta))+d4*(diff(h2(theta), theta, theta, theta))+d5*h3(theta)+d6*(diff(h3(theta), theta, theta))+d7*(diff(h1(theta), theta, theta, theta, theta)) = 0, d8*h2(theta)+d9*(diff(h2(theta), theta, theta, theta, theta))+d10*(diff(h2(theta), theta, theta))+d11*(diff(h1(theta), theta))+d12*(diff(h1(theta), theta, theta, theta))+d13*(diff(h3(theta), theta))+d14*(diff(h3(theta), theta, theta, theta)) = 0, h3(theta)^5*(d16+ln(h3(theta))^2*d15+2*ln(h3(theta))*d17)+(diff(h3(theta), theta, theta))*h3(theta)^4*(d19+ln(h3(theta))^2*d18+2*ln(h3(theta))*d20)+(diff(h3(theta), theta, theta, theta, theta))*h3(theta)^4*(d22+ln(h3(theta))^2*d21+2*ln(h3(theta))*d23)+h1(theta)*h3(theta)^4*(d25+ln(h3(theta))^2*d24+2*ln(h3(theta))*d26)+(diff(h1(theta), theta, theta))*h3(theta)^4*(d28+ln(h3(theta))^2*d27+2*ln(h3(theta))*d29)+(diff(h2(theta), theta))*h3(theta)^4*(d31+ln(h3(theta))^2*d30+2*ln(h3(theta))*d32)+(diff(h2(theta), theta, theta, theta))*h3(theta)^4*(d34+ln(h3(theta))^2*d33+2*ln(h3(theta))*d35)+h3(theta)^4*(d37+ln(h3(theta))^2*d36+2*ln(h3(theta))*d38)+h3(theta)^4*(diff(h2(theta), theta, theta, theta, theta, theta, theta))*(d40+ln(h3(theta))^2*d39+2*ln(h3(theta))*d41)-beta*h3(theta)^3*d42-chi*ln(h3(theta))^2*d43/kappa-chi*d45/kappa-2*chi*ln(h3(theta))*d44/kappa = 0, h1(0) = 0, h1(1) = 0, h2(0) = 0, h2(1) = 0, h3(0) = 1, h3(1) = 1, ((D@@1)(h1))(0) = 0, ((D@@1)(h1))(1) = 0, ((D@@1)(h2))(0) = 0, ((D@@1)(h2))(1) = 0, ((D@@1)(h3))(0) = 0, ((D@@1)(h3))(1) = 0, ((D@@2)(h3))(0) = 0, ((D@@2)(h3))(1) = 0}; dsol6 := dsolve(dsys4, 'maxmesh' = 600, numeric, output = listprocedure)

Hy all.

I want to solve this equation, with„dd” as numerical result. What do I do wrong? Thanks. Nico

TTot := 70;
TC := 17;
GM := .26;
QMax := 870;
V := 3600*GM*QMax*TTot;
eq := V = int(QMax*exp((-t+TC)/dd)*(1+(t-TC)/TC)^(TC/dd), t = 0 .. TTot);
fsolve(eq, dd);


I have a system of diff equations (see below). I am trying to obtain analytical solution. when I assume that z=wN, I receive such solution. Do anybody have idea if I know that z>wN, does this system has an analytical solution?

diff(K(t), t) = -(1/2)*(Q(t)^2*alpha^2*eta*upsilon-2*eta*alpha*(N*upsilon*w*C[max]-z*alpha*K(t))*Q(t)+N*w*(-2*C[max]*z*eta*alpha*K(t)+upsilon*((-N*w+z)*alpha+N*C[max]^2*w*eta)))*K(t)/((C[max]*w*N-alpha*Q(t))*upsilon*N*w)

diff(Q(t), t) = (1/2)*(-z*(Q(t)^2*alpha^2*eta-2*N*Q(t)*alpha*eta*w*C[max]+w*(w*(eta*C[max]^2-alpha)*N+z*alpha)*N)*K(t)-2*N*upsilon*w*(N*w-z)*(C[max]*w*N-alpha*Q(t)))/((C[max]*w*N-alpha*Q(t))*upsilon*N*w)

K(0) = K0, Q(0) = Q0




sin(xy) = x + y

subs( y(x)=y, solve( diff(subs( y=y(x), (1) ),x), diff(y(x),x) ) );


subs( x(xy)=x, solve( diff(subs( x=x(xy), (1) ),xy), diff(x(xy),xy) ) );


I can not get this answer to come out correctly when using this software please help. the correct answer in the back of the book is 


1- y cos(xy)


x cos(xy) - 1


And is there a way that this program can tutor me on how to get this answer intead of spitting out the answer 

the diff tutor only allows for a one sided equation to be entered.

I have a system of first order diff. equations which I would like to solve symbolically. Unfortunately, Maple does not solve the system. Do anybody have suggestions how can I solve this system (please see below):

diff(S(t), t) = -eta*(C[max]*w*N-alpha*Q(t))*K(t)*S(t)/(w*N*(S(t)+K(t))),

diff(K(t), t) = S(t)*((z*eta*alpha*(C[max]*w*N-alpha*Q(t))*S(t)-upsilon*(eta*alpha^2*Q(t)^2-2*C[max]*w*N*eta*alpha*Q(t)+((-N*w+z)*alpha+N*C[max]^2*w*eta)*N*w))*K(t)^2+(2*((1/2)*z*eta*(C[max]*w*N-alpha*Q(t))*S(t)+N*w*upsilon*(N*w-z)))*S(t)*alpha*K(t)+N*S(t)^2*w*alpha*upsilon*(N*w-z))/((K(t)^2*alpha*z+3*S(t)*K(t)*alpha*z+S(t)*(2*S(t)*z*alpha+upsilon*(C[max]*w*N-alpha*Q(t))))*(S(t)+K(t))*N*w),

diff(Q(t), t) = (-alpha*z*(z*eta*(C[max]*w*N-alpha*Q(t))*K(t)+N*w*upsilon*(N*w-z))*S(t)^2+(-z^2*eta*alpha*(C[max]*w*N-alpha*Q(t))*K(t)^2-(eta*alpha^2*Q(t)^2-2*C[max]*w*N*eta*alpha*Q(t)+N*w*((2*N*w-2*z)*alpha+N*C[max]^2*w*eta))*z*upsilon*K(t)-N*w*upsilon^2*(N*w-z)*(C[max]*w*N-alpha*Q(t)))*S(t)-N*w*z*alpha*upsilon*K(t)^2*(N*w-z))/((2*S(t)^2*alpha*z+(3*z*alpha*K(t)+upsilon*(C[max]*w*N-alpha*Q(t)))*S(t)+K(t)^2*alpha*z)*N*w*upsilon)

where initials conditions are:

S(0) = S0, K(0) = K0, Q(0) = Q0






Hello guys ...

I used a numerically method to solve couple differential equation that it has some boundary conditions. My problem is that some range of answers has 50% error . Do you know things for improving our answers in maple ?

my problem is :



suggestion method by preben Alsholm:

a,b,c,d,e,j,h are constants.suppose some numbers for these constants . I used this code:



I used digits for my code at the first of writting.

please help me ... what should i do?

Hello guys, i have a system of equations ( dynamical system ) which i have its critical points but when i compute its critical points with maple i get different points , i dont know what is wrong . thank you for your time.

Hello Hello everybody 
   I have to solve the following differential equation numerically 




mb:=765 : mp:=587 : Ib:=76.3*10^3 : Ip:=7.3*10^3 : l:=0.92 : d:=10: F:=490: omega:=0.43 :


1352*(diff(diff(x(t), t), t))+587*(10*cos(theta(t))+.92*cos(alpha(t)+theta(t)))*(diff(diff(theta(t), t), t))+540.04*cos(alpha(t)+theta(t))*(diff(diff(alpha(t), t), t))+5870*(diff(theta(t), t))^2*sin(theta(t))+540.04*(diff(theta(t), t)+diff(alpha(t), t))^2*sin(alpha(t)+theta(t))-490*sin(.43*t) = 0



1352*(diff(diff(z(t), t), t))-5870*(sin(alpha(t)+theta(t))+sin(theta(t)))*(diff(diff(theta(t), t), t))-540.04*sin(alpha(t)+theta(t))*(diff(diff(alpha(t), t), t))+5870*(diff(theta(t), t))^2*cos(theta(t))+540.04*(diff(theta(t), t)+diff(alpha(t), t))^2*cos(alpha(t)+theta(t))+13263.12-490*sin(.43*t) = 0



587*(10*cos(theta(t))+.92*cos(alpha(t)+theta(t)))*(diff(diff(x(t), t), t))-587*(.92*sin(alpha(t)+theta(t))+10*sin(theta(t)))*(diff(diff(z(t), t), t))+(142796.8368+10800.80*cos(alpha(t)))*(diff(diff(theta(t), t), t))+[7796.8368+5400.40*cos(alpha(t))]*(diff(diff(alpha(t), t), t))-587*sin(alpha(t))*(9.20*(diff(alpha(t), t))^2-9.20*(diff(theta(t), t)+diff(alpha(t), t))^2)+5297.7924*sin(alpha(t)+theta(t))+57584.70*sin(theta(t)) = 0



540.04*cos(alpha(t)+theta(t))*(diff(diff(x(t), t), t))-540.04*sin(alpha(t)+theta(t))*(diff(diff(z(t), t), t))+(7796.8368+5400.40*cos(alpha(t)))*(diff(diff(theta(t), t), t))+7796.8368*(diff(diff(alpha(t), t), t))-5297.7924*sin(alpha(t)+theta(t))+5400.40*(diff(theta(t), t))^2*sin(alpha(t)) = 0


CI:= x(0)=0,z(0)=0,theta(0)=0,alpha(0)=0,D(x)(0)=0,D(alpha)(0)=0,D(z)(0)=0,D(theta)(0)=0;

x(0) = 0, z(0) = 0, theta(0) = 0, alpha(0) = 0, (D(x))(0) = 0, (D(alpha))(0) = 0, (D(z))(0) = 0, (D(theta))(0) = 0


solution:=dsolve([eq1,eq2,eq3,eq4, CI],numeric);

Error, (in f) unable to store '[0.]/(0.17571268341557e16+[-0.25659510610770e15])' when datatype=float[8]




I don't know why it says : Error, (in f) unable to store '[0.]/(0.17571268341557e16+[-0.25659510610770e15])' when datatype=float[8]


Help pleaase!

thank you !!!

Download systé


Hello all,

I'm an engineering student working on bicycle shifting. After an dynamic study i encounter the equation:


where C is a real constant

More exactly, i would need to find a formule for theta12 using the succesive derivatives of theta10.

I heard that i need to search a numerical solution but,up to now, don't succeed to solve it.

I'm open to all idea.


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