Hi, assume  i have some data and want to fit a model function to it (Maple12). The help pages show a way:

with(Statistics):
X := Vector([1, 2, 3, 4, 5, 6], datatype=float):
Y := Vector([2, 3, 4.8, 10.2, 15.6, 30.9], datatype=float):

f:=a+b*exp(c*t);

Fit(f, X, Y, t);

It works as expected. Now assume that the model function is not explicitly given,  it may be just the solution of a  differential equation:

f:=diff(y(t),t)+u*y(t)=v; y(0)=0

K heres my problem.

Say i have a function, for example y=(1-x) and i want to find out which values of x will give me a real answer (i.e. no complex numbers!)

Preferrable i would like the output to be something along the lines of... "y is real for a<x<b..."

Hello,

Is there a way to merge two lists?

For example, to merge:
a=[[1,2],[3,4]]
b=[[5,6],[7,8],[9,10]]

and get:
[[1,2],[3,4],[5,6],[7,8],[9,10]]

Thanks

I need your help and guidance to resolve
this problem.

Simplify expression under summation. How could simplify the expression inside the sum, as much as possible. I have tried with:

simplify, expand, Normalize, Power...

But do not get the results I want.

Title allready says it all. I want to create a 2D plot in the xy-plane of e.g. x^(3/2) + y^(3/2) = 1 How do I do that? -.^

I get the proper graph with this function however I need to zoom on the intersection to show that the limit does not exist.

implicitplot3d((x^2-y^2)/(x^2+y^2), x = -.5 .. .5, y = -.5 .. .5, z = -2 .. 2, grid = [30, 30, 30])

 

 When I enter this function, I only get a blank plot window.  When I drag and drop it in the plot window I get an error.

implicitplot3d(z = xy^2/(x^2+y^4), x = -4 .. 4, y = -4 .. 4, z = -.5 .. .5, grid = [30, 30, 30])

  Any help is greatly appreciated,

 Jim Z

Hey!

So I am trying to write a nifty little program to show that for any x^n Leibiz method of dividing the area under the curve into rectangles of base r,r^2,r^4... so on, can this be done?

 

Thanks!

#96

r=625       theta=pi/2

I found the 4th root of 625....it = 5.

Now, I'm supposed to use DeMoivre's Theorem. Then divide pi/2 by 4 and add k/4 times 2pi with k going between 0 and 3.

The 2nd angle should be 5pi/8, third should be 9pi/8, and the last should be 13pi/8.

((Show me how please. Thanks!))

#30

llvll=3              u=<4,-4>

-Find the magnitude of the given vector and divide each of the components by that magnitude. That will produce a unit vector that is the same direction of the given vector. Since it wants the magnitude to be equal to 3, multiply each component by 3. Make sure the radicans are out of the denominator. The answer should be a vector in component form.

 

#48

llvll=3            u=3i+4j

I am trying to find the stationary ponts of f(x,y) 5*x^3-12*x-3*x*y+6*y^2-4;

so far, I have got

A:=diff(f,x)=0

B:=diff(f,y)=0

e1:=RootOf(A,x)

e2:=RootOg(B,x)

G:=solve([A,B],[x,y])

do I now need to use allvalues?

 

if so, I get

 

V:=allvalues(G). This gives me two values of x and y.  (one with a positive root and one with a negative root)

ie. v=[[x=c - sqrtb,y=4c - 4sqrtb],[x=c+sqrtb,y=4c+4sqrtb]]

r:=diff(f,x$2) =30x

s:=diff(f,x,y) = -3

I am trying to find the stationary ponts of f(x,y) 5*x^3-12*x-3*x*y+6*y^2-4;

so far, I have got

A:=diff(f,x)=0

B:=diff(f,y)=0

e1:=RootOf(A,x)

e2:=RootOg(B,x)

G:=solve([A,B],[x,y])

do I now need to use allvalues?

 

if so, I get

 

V:=allvalues(G). This gives me two values of x and y.  (one with a positive root and one with a negative root)

ie. v=[[x=c - sqrtb,y=4c - 4sqrtb],[x=c+sqrtb,y=4c+4sqrtb]]

r:=diff(f,x$2) =30x

s:=diff(f,x,y) = -3

hey there! I was woundering.. What is the command for an ordinary plot, to lable the points on the x-Axes at points, like π, 2π, 3π and so forth. It would be very usefull for plots of trigonometric functions. I didn't find the option in the Help page. What i found, is the option by right clicking on the plot - but it is greyed out most time, and i would like to know the command anyway, so it would allways plot right, when i re-execute the Maple document. cheers!

I need to solve this by using polar form.

(2-5*i)^12/(4+i)^11

I found polar in the help section and used it like this:

polar((2-5*I)^12/(4+I)^11);

Is that it or is there something else I need to do?

I am using Maple 12.01 and I am using dsolve to solve a second order ODE;  example :

eq:=diff(y(t),t,t)+sin(t)*diff(y(t),t)+y(t)^2-5*y(t)=0;

ic:=a->[D(y)(0)=0,y(0)=a]; # initial conditions.
 

I want to investigate the  values of z(t, y, y') when g(t, y,y') = 0. Here z might be y''' or cos(t y') and g  might be y(t)-4.

What I would like to do is create an Array whose nth entry is of the form [ tn, z(tn,y(tn), y'(tn)]  where tn is the nth value of t at which the condition g(t, y,y') = 0 is satisfied.

Hi all,

I am assuming this is a pretty easy thing to do. I am solving a system of differential equations, and then want to export my results to maple. I basically want the solution to the system for 40 time steps (counting by 5).

By hand this is