I've got a rain drop falling through air with velocity V=[vx,vy] when exposed to to dragforce Fd

formulas in following link 

Exposed_for_drag_force.docx

But  Fd= (expression for dragforce*v)* V

How to multiply V=[vx,vy] and recive list for all values so i can make a plot with this values?

need to use Cd= V ->… and returns Cd(v) (not proc..)

What am I missing?  Why it is not trivial to ask Maple to find all nth roots of a complex number in standard a+ib form or polar form and receive the answer in simplified polar form as it would be shown in any Trigonometry or PreCalculus textbook?

Hi,

I can't quite figure out out which element in list b or list rts-x1 is closest to zero.
 

Download Closest_value_to_zero_in_a_list.mw

Hi there, I'm a really noob when it comes to maple.
My teacher wants me to solve a differential equation using this software and the only problem I have is that I dont know which command to use to solve the equation with boundary conditions.
I've already tried the dsolve command but then I realized that it only works with initial conditions, and the conditions I have are boundary (initial-end). So how do I actually solve the differential equation ?

When I download the help document here

https://www.maplesoft.com/support/help/maple/view.aspx?path=int%2Fdetails

I get a bug when I execute the page.

I copied pasted the last line using 1d math notation to replicate the error.

There is no addition symbol between x^2 + O(x^5)

On the help page I don't see an error. 

 I uploaded the help file   int-details_(2).mw 

Hello people in mapleprimes,

I hope you will help me about modifying an expression.

How can I factor the expression with w and Delta__1 in the attached file?

e2_3 := w^(1-sigma)*((f__11*sigma*Delta__1/L__1)^(-1/(sigma-1))/w)^(k-sigma+1)*k/(Delta__1*(k-sigma+1)*a__0^k);

Thank you for advance.

Modifying_expression_factor.mw

how can i simplify with definition two new parameter 

i show in this picture

ii := evalr(csch(INTERVAL(-infinity .. -1, 1 .. infinity)));
             INTERVAL(-csch(1) .. 0, csch(1) .. 0)

evalr(ii-ii);
                            -csch(1)

(Make sure you don't have the Typesetting level set to Extended, or ii won't be displayed correctly.)

There are no functions to test for interval membership (or to compute intersections/unions of intervals), so it's unclear how Maple treats the interval csch(1)..0, but apparently evalr is getting tripped up by it.

Also:

evalr(sech(INTERVAL(-infinity .. -1, 1 .. infinity)));
                               0

evalr(arccsch(INTERVAL(-infinity .. -1, 1 .. infinity)));
Error, (in evalr/arccsch) too many levels of recursion

Hello,

For example, let's say we have the following function

Now if we want to calculate the value of a function we have to

subs([x1=10,x2=20],eval(hf));

My question is the following: How to substitute values for x1 and x2 using values from vector? something like that

x:=[10,20];

subs([x],eval(hf));

Best,

Rariusz

 Hello,

I solve a partial differential equation using the THETA METHOD on Maple17, but what is also of essence is the skin friction and Nusselt Number which are {diff(u(x, t), x)} at x = 0 and {diff(T(x, t), x)} at x = 0 respectively. How can I achieve the two using the THETA METHOD? This is the PDE in it full flesh. 

 PDE := {diff(phi(x, t), t) = (diff(phi(x, t), x, x))/S__c, diff(u(x, t), t) = diff(u(x, t), x, x)-M^2*(u(x, t)+m*w(x, t))/(m^2+1)-u(x, t)/`ϰ`-2*Omega^2*w(x, t), diff(w(x, t), t) = diff(w(x, t), x, x)+M^2*(m*u(x, t)-w(x, t))/(m^2+1)-w(x, t)/`ϰ`+2*Omega^2*u(x, t), diff(theta(x, t), t) = lambda*(diff(theta(x, t), x, x))/P__r+D__r*(diff(phi(x, t), x, x))}

With conditions: BC := {phi(0, t) = 1, phi(12, t) = 0, phi(x, 0) = 0, u(0, t) = t, u(12, t) = 0, u(x, 0) = 0, w(0, t) = 0, w(12, t) = 0, w(x, 0) = 0, theta(0, t) = 1, theta(12, t) = 0, theta(x, 0) = 0}

Where the parameter like P_r, S_c  e.t.c are constants to assign value to.

Thanks.

I want to plot the compex solutions of a single equation. I do

> plot([fsolve(x^3 = 1, complex)])

The output consists of a warning:

"Warning, unable to evaluate 2 of the 3 functions to numeric values in the region; complex values were detected"

and a horizontal line.

What am I doing wrong?

Thank you!

The linked worksheet displays the geodesic between two points on a surface z(x,y).

Surfacepath.mw

Gradient descent will find a stepped approximate path of fastest descent between the points, but is there a way to find a function defining an exact i.e. smooth path of fastest descent? If so, how can a precise time of fastest descent be determined?

Namely, I mean

solve({y >= 4*x^4+4*x^2*y+1/2, sqrt((1/2)*(x-y)^2-(x-y)^4) = -2*x^2+y^2}, [x, y]);
                               []

The answer (no solution) is not correct in view of 

eval({y >= 4*x^4+4*x^2*y+1/2, sqrt((1/2)*(x-y)^2-(x-y)^4) = -2*x^2+y^2}, [x = 0, y = 1/2]);
      {(1/8)*sqrt(4) = 1/4, 1/2 <= 1/2}
eval({y >= 4*x^4+4*x^2*y+1/2, sqrt((1/2)*(x-y)^2-(x-y)^4) = -2*x^2+y^2}, [x = -1, y = -3/2]);
      {(1/8)*sqrt(4) = 1/4, -3/2 <= -3/2}            

Hi all, I want to ask how to use for loop reverse in Maple.

Example, i have array . In Java then

for(int i = arr.size(); i > 0; i--) {

    //do something

}

What is simillar for loop in Maple?

Thank you very much.

Hi, when I wan to generate results, it shows this; What should I do?

Error, (in solve) a constant is invalid as a variable, I.