## Rounding very small numbers to zero...

Hi - Is there a way to tell Maple to zero out terms in an expression that have a very small constant. For example I would like to round something like (1x + 2y - (1x10^-20)z) to (1x + 2y). Thanks. Bryan

## plot a function...

Hereby I'm telling you I'm new in using Maple, so please don't laugh after reading my problem. I want to plot the function x=6. In my brain this is a vertical line, through the x-axis with x=6. After several attempts, the only thing I get is a horizontal line through y=6. Where did I go wrong? > x:=6; > plot(x);

## Coupled diff eq using Rkf45...

(D@@2)(x)(t)=(-g/v)*sqrt(D(x)(t)^2+D(y)(t)^2)*D(x)(t)
(D@@2)(x)(t)=g-g/v*sqrt(D(x)(t)^2+D(y)(t)^2)*D(y)(t)
initial conditions
x(0)=0,y(0)=0,d(x)(0)=134,d(y)(0)=0
using rkf45
for time, 0-30
solve for x(t),y(t)
then i plan to plot the two and find the intersection
but i'm having trouble getting through the rkf45 to get my x(t) and y(t)

## Multiple Mapping...

I intended to post this msg in this forum but somehow put into the MAPLE TA forum. Here it is where it belongs. I know this is a really basic question & I'm kind of surprised I haven't run into this situation before, but here goes. Multiple assignments are possible, e. g. a,b,c = 1,2,3 What's the simplest MAPLE command(s) which will place into each of these 3 variables a value twice its previous value. I try stuff like a,b,c = map(x->2*x,(a,b,c)) and MAPLE says no way!

## coupled differential equations...

how do i solve a set of coupled differential equations like these for x(t) and y(t) eqn1 := (D,2)(x)(t) = -a*sqrt(D(x)(t)^2+D(y)(t)^2)*D(x)(t), eqn2 := (D,2)(y)(t) = g-a*sqrt(D(x)(t)^2+D(y)(t)^2)*D(y)(t)

## Nice numerical trouble

by: Maple
Playing with numerics for the hypergeometric function 2F1 i stumbled into the following exactness stuff, where lots of digits are lost and one needs to increase working precision quite a lot to get a good answer: f1 and f2 result from evaluating ugly, but usual transcendent functions, f3 comes through high precision and f0 is the limiting case.
```  restart;

hypergeom([1,2+epsilon],[3],z):
'%' = simplify(convert(%,StandardFunctions));
theSol1:=rhs(%):

theSol1 = -2*(z*(1-z)^epsilon*epsilon-1+(1-z)^epsilon)/
z^2/((1-z)^epsilon)/epsilon/(1+epsilon);
is(%);
```

## Surface Coloring...

Hi, Im using the display command to plot 3d surefaces/projections (which the also overlap on different occasions)on the same graph coming from different equations. My question is how can i colour the surfaces with a command (its too hard to do it onthe graph)so i know to which equation each surface corresponds to? Is there an additional way offered from maple to distinuish the graphs from each other. Finaly, I use the command labels=[x,y,z] to call my axis "Time of Fault Clearance,s" , "Magnitude of Fault Current" , "Parametr".How do i syntax a string? Thanks for your time

## Creating a Matrix using nested for loops like in m...

Below is the code I'm trying to get working. In matlab this would be cake, but I can't seem to figure out how to get this working in Maple. Help Please.... > for j from 1 by 1 to 6 (for n by 1 to 6 do M[j,n]:=(∫)[o]^(l)(phi)[j]*(phi)[n]*p ⅆx end) end do; Error, invalid sequence for j from 1 by 1 to 6 (Typesetting:-mambiguous(for , Typesetting:-merror( Ok I also can't get my code to past in..... urgh...

## Make all tabs appear at top...

Hi, I am having a problem with making all of my worksheets appear as tabs. Maple only displays a worksheet and then I have to use the back or forward arrows or the "more" windosw pull down to activate a sheet. I have had all the worksheets appear as tabs above the worksheet before, but cannot figure out how I did this. I am using Student Maple 10. Can anyone tell me how to make them appear as tabs? I have check what I think is the appropriate box.. open worksheets in new tab. TIA Larry Ciak aka malt_master@comcast.net

## I have an expression result that incorporates D(k)...

what does that mean? I cannot find it on the help?

## testing equivalence of relations...

Hello, my question is connected to the topic in my blogpost - Testing objects for equivalence. Alec Mihailovs wrote a procedure for nested verifications. But this doesn't work for relations where one relation equals to the second one multiplied by a constant. They are different, but solution is the same. For example: x=1 2*x=2 also Maple answers false. `verify(x=1, 2*x=2,relation);` false

## Triangle brackets...

Hi, I have a question. In the Classic Worksheet in Maple 10, how do we change the triangle brackets <> to the square brackets [] when entering matrices with the Matrix palette. Thanks

## second derivative to find inflection points...

I have found the second derivative of a function, but am unable to identify the correct command in maple that will allow me to solve for my variable when the derivative is equal to zero. I am attempting to identify the points of inflection. I thought that the command would be similar to the one I used for the first derivative, but it is not working. This is what I tried. (D(D(f)(x)),=0.0,x); I used D(D(f)(x)); to find my second derivative. I used D(f)(x); to find my first derivative and (D(f)(x)),=0.0,x) to find all points where x was equal to zero for my first derivative. I have also tried (D@@2)(f); with no success.

## Using the del operator and diff with respect to a ...

Hi I need to use the 'del' operator form with both subscript and superscript acting on it. I would for example like to be able to differentiation of a function that combines a number of vectors with respect to a particular vector. I then need to take the components for example (x) corresponding to the subscript on the del operator. Is there an easy way to do this? I can perhaps make it simpler by just using the standard derivative, but dont know how to do this with respect to a vector. Could someone help out a newbie here. I can then take the dot product with a unit vector in the x direction to obtain just the x component.