Hello,

I have a problem with my coursework.

Here it is: how to generate a random data points (x_k,y_k) for k=1,2,3,...30

I know how to do  (more or less) the rest of the task but to generate this points no way!"!! Please anyone can help me???

Thanks

 

 

Hi all,

I am doing some research requiring solving a system of differential equations.

Excuse me for my English, I'm Dutch)    

I have a excersice I have to make in Maple, but i don't have a clue on how to do it. I will just type it here and see what the response is.

If somebody has the Calculus book written by James Stewart, it's the "Discovery Project" on page 1040..

The figure shows the solid enclosed by three circular cylinders with the same diameter that intersect at right angles/ In this project we compute its volume and determine how its shape changes if the cylinders have different diameters.

Hi, I'm trying to find the steady states of a pair of ODEs and have used the code below but i get the message "warning, solutions may have been lost".

 

> restart;

> with(LinearAlgebra);

> f := (u, v) -> (u*(1-u))-a*(u*v/(v+u);

> g := (u, v) -> b*v(a(u/(v+u))-d);

> du := diff(u(t), t) = f(u(t), v(t));

> dv := diff(v(t), t) = g(u(t), v(t));

> steadystates := solve({f(u, v) = 0, g(u, v) = 0}, {v, u});

Warning, solutions may have been lost

 

Here is a problem that cause me trouble in Maple.  Maybe it's a careless mistake, or worst, a mathematical mistake (hope not).  Can someone can help me?

View 3867_inconsistent.mw on MapleNet or Download 3867_inconsistent.mw
View file details

Hello,

I have some difficulties with the transfert function of a circuit. After a lot of simplification I find this equation:

R*C*diff(v(t),t)+v(t)=i(t) with R=K / i(t)

I have never seen this kind of equation before, I hope someone could help me, google is un-useful to this.
Then, I would solve this for a heavyside and sinusoidale current. How can I make a heavyside with maple ?

Thanks,
Ben

Hi!,

I've a problem with special waveforms like Square, Triangular and SawTooth. I've to solve a RLC circuit ODE for the capacitor's charge  (q(t)) as a function of time with an Voltage input of a Square Waveform, Triangular WaveForm and a SawTooth Waveform. I solved the problem with one oscillation for each waveform, but the problem says that we have to work with the periodical characteristic function for each of them.

My question : How can I transform one oscillation in a periodical function with maple? (repeating that oscillation along the time).

Why can I not get a common denominator from a/2+b/3?  Maple returns 1/2*a + 1/3*b and not (3a+2b)/6.  Normal(a/2+b/3) returns the same equation.

If I simplify(a/b+b/c) I get (a*c+b^2)/(b*c) but doesn't seem to work right with numbers in there.   

 

need help

Hi. I have a simple problem here. I only need one result from a result list that maple gives me. As you can see below. I need the value of the variable F. But maple does not give me a single result (in this case 2), it gives me many. So how do i tell maple to give me only the first result (1.0353)? > evalf[5](solve(K = S*F^n, F));

Consider a tree that is planted at time t=0, and let V(t) denote its value at time t. The rate of interst is 100r per cent per year and is continously compounded.

a) Derive an expression for the present value of the tree.

b) The optimal time to cut down the tree is the value of t that maximise the present value of the tree. Derive the condition this optimal time must satisfy.

c) Explain what the condition means in plain language.

Consider the following model of an open economy          Y- C(Y) - X(e) = C

Question:   Consider a firm that sells in two separate markets. The inverse demand functions in the two market are  p₁= a₁-b₁.q₁    

                     and   p₂ = a₂ -b₂.q₂      and the total production   c(q) = a. (q₁+q₂)