How do I use to compute d(logS(t)) and use this to find the closed form solution of S(t)

Hello

Just started out with maple. 

I entered a function that looks like this, to find the volume of a sphere: V := (4*Pi(d/2)^3)/3

then I use the eval command like this: eval(V, d = 6.35*mm)

and I get this:(4*Pi(3.175000000*mm)^3)/3

Anything I tried, maple doesn't want to spit out one number! I just need what that is equal to, I don't need an expression with Pi. Spent over two hours trying to figure it out, watching videos etc but no luck! hoping that someone can help me with this!

Is there any way to get maple to use zero index offseting?

n[0] actually represents the first element?

Syrup has awsome functionality but it only installs halfway.  I have tried to run Maple as administrator and install from File - Open From Cloud. Is there a better way ?

Hello there, 

Would you please have a look at this question?

I got the answer in the 'eq_4_35', but what I wanted to see is the 'desired' expression. 

Somehow, the term '3*C' doesn't want to go away from the 'x__0' term, thus I wonder there is a way to cancel the term in the expression. 

Download Q20201005_2.mw

Hi

I have the following of fractional of ode system.

.How to solve it by maple.

Just curious about an output in an if statement.

Why do I need to use Print() in an if statement, when I don't need it otherwise? Why doesn't "hei" show in the output of the attached example?

Printinloop.mw

Charging a capacitor with a DC is well known and interaction with a sinusoidal signal is known to perfection.

The mathematical solutions behind an arbitrary waveform V1(t) is hard or impossible? to find .

To simplify, the arbitrary wave can be expressed with a 2-d degree polynom. This gives a fairly simple

expression with an integral. The problem however is that V2(t) - the capacitor voltage - appears on both sides and maple seems unable to resolv this into a symbolic expression.

If this can be solved it would be great ! The solution should be of the symbolic form V2(a,b,c,V2start,t1,t2,RC) and give the answer what voltage the capacitor V2 would reach arter charging between t1 and t2  with a V1(t) that is changing during charge.

Professor Robert J. Lopez is a Maple Fellow and the author of many Maple webinars and applications. He is also co-author of a book entitled Discovering Calculus With Maple, which I have recently acquired, and which turns out to be keyed to Maple V Release 3 on a Mac. Well, I have Maple 2020 on a Mac. What is the best way to get this book to work for me?  Thanks very much.

How do I plot the complex function |z+1||z-1|=1 in Maple? I know there is complexplot but don't quite understand how to use it.

I'm trying to readin a XML file, where some figures are attached a unit.

Here's part of the XML file.

When doing the readin and assigning the values to  a variable with AttributeValue, the type of the variable is a string.

How can I convert this string value ("10.*Units:-Unit(m)") to a number attached the defined units?

hello,

My equations are not getting solved.

Please tell me, is there any other command to solve these type of equations.

Q1.mw

Hi,

How to keep fractions and parentheses in the expression, and not calculate the product ?

Thanks

QuestionFraction.mw

For example this fraction?

Why Maple gives different looking solution when calling  

dsolve(sys);

vs.

dsolve(sys,deps);

? Both solution are actually correct. But look different.  Here is an example

restart;
sys:=[
diff(x(t),t) = 2*x(t)-z(t), 
diff(y(t),t) = 2*y(t)+z(t), 
diff(z(t),t)=2*z(t),
diff(w(t),t)=-z(t)+2*w(t)];
deps:=[x(t),y(t),z(t),w(t)];

dsolve(sys);

dsolve(sys,deps);

Notice the difference:

In first case, the x(t) and y(t) solutions have 2 constants of integrations, and in the second case, they have 3 constants of integration.

If we solve this using the matrix exponential method, the solution comes out to match the first one:

A:=Matrix([[2,0,-1,0],[0,2,1,0],[0,0,2,0],[0,0,-1,2]]):
sol:=Vector([x(t),y(t),z(t),w(t)])=LinearAlgebra:-MatrixExponential(A,t).Vector([_C1,_C2,_C3,_C4]);
simplify(sol)

Again, both solution verify to 0, using odetest, and I assume now it is correct (have no reason to think odetest is not correct).

But I'd like to understand more why when passing the unknowns to dsolve, the solution comes out different looking (3 constants of integrations, vs. two in this case). Should the solution be the same looking in both cases? 

This came out, since I thought my solution was wrong, since it did not look like Maple's. 

Maple 2020.1

In a recent question, the solution involved [...]::[list$3].

H:= proc(n, x, y)
    if n=0 then y+1
    elif n=1 and y=0 then x
    elif n=2 and y=0 then 0
    elif y=0 then 1
    elif not [n,x,y]::[nonnegint$3] then 
        'procname'(n-1, x, 'procname'(n, x, y-1))
    else
        thisproc(n-1, x, thisproc(n, x, y-1))
    fi
end proc

Where is  the  form [...]::[list$3] documented?