## 2530 Reputation

15 years, 172 days

Dr. Robert J. Lopez, Emeritus Professor of Mathematics at the Rose-Hulman Institute of Technology in Terre Haute, Indiana, USA, is an award winning educator in mathematics and is the author of several books including Advanced Engineering Mathematics (Addison-Wesley 2001). For over two decades, Dr. Lopez has also been a visionary figure in the introduction of Maplesoft technology into undergraduate education. Dr. Lopez earned his Ph.D. in mathematics from Purdue University, his MS from the University of Missouri - Rolla, and his BA from Marist College. He has held academic appointments at Rose-Hulman (1985-2003), Memorial University of Newfoundland (1973-1985), and the University of Nebraska - Lincoln (1970-1973). His publication and research history includes manuscripts and papers in a variety of pure and applied mathematics topics. He has received numerous awards for outstanding scholarship and teaching.

## Control+Shift+R...

This works in every version of Maple, Maple 15 included.

The first "How do I" question answered in the Maple Portal's Student version is "How do you set a piecewise function in Maple?" The detailed example that gives the answer shows how to add an additional "row" or rule to the piecewise template inserted from the Expression palette.

## Typesetting Rules Assistant...

Select "Typesetting Rules" in the View menu to launch the Typesetting Rules Assistant. In the lower left corner make the two changes shown in the following figure.

The exact syntax needed for this is somewhere in my Little Red Book of Maple Magic, but that's no longer handy; so I tend to use the Assistant rather than go look up the syntax.

## NewtonsMethod command...

If all you want  is to see the iterates, use the NewtonsMethod comand in the Student Calculus1 package. It has an option to return a graph (or an iteration) of the approximation process. Better yet, use the Newton's Method Tutor available from the Tools/Tutors menu. This tutor implements the NewtonsMethod command in a syntax-free way.

## list or set...

I'm going to guess that instead of supplying to dsolve a single list or set, inside the set braces you have grouped the equations and/or initial conditions as a list or set.

## By parts, stepwise...

The following Maple code will apply integration by parts repeatedly, generating the asymptotic expansion "stepwise." I did not see the asymptotic expansion in Maple's FunctionAdvisor.

with(IntegrationTools):
n:=5:
q := Int(1/ln(t), t = 0 .. x);
for k to n do
q := simplify(Parts(q, GetIntegrand(q)));
end do;

The Parts command applies integration by parts to an inert integral (set with Int) or to an expression containing such. The second argument is the factor that is to be differentiated. That factor is the integrand of each integral appearing, so the GetIntegrand command simplifies the coding. Of course, n can be set to any desired positive integer.

## Calculus Study Guide...

Section 1.2 of the Calculus Study Guide deals with the epsilon-delta definition of a limit. The approach taken involves solving equalities rather than inequalities. Use equations such as f(a+delta_right)=L+epsilon and f(a-delta_left)=L-epsilon to obtain delta(epsilon) for an increasing function whose limit at x=a is L. Maple's ability to solve equations for the bounds on delta is greater than its ability to solve the inequalities inherent in the epsilon-delta definition of a limit. For a nonlinear function f, delta_right and delta_left will in general be different; the trick is to pick the smaller of the two bounds to obtain a single delta(epsilon) needed in the definition.

RHIT where I developed most of my Maple materials is primarily an engineering school. Interpret that as it is intended; purists might feel that no calculus course can ever be complete without mastery of the epsilon-delta definition of a limit. The Calculus Study Guide devotes a single section to this definition on the grounds that those in need of a study guide probably do not need to master this definition in the first calculus course. But please, no flaming here. I'm just expressing my opinion in the freedom of retirement.

## Built-in tools...

The built-in command

Student:-VectorCalculus:-TNBFrame(<cos(t),sin(t),t/10>*3/2, 'output'=animation, 'axes'=frame, 'range'=0 .. 4*Pi, 'frames'=30,caption="");

will produce an animation of the TNB frame moving along the helix in Rouben's worksheet. In fact, the animation could be created with the SpaceCurves Tutor, and the command that generates the animation copied and pasted from the bottom of the tutor. The tutor (and the underlying command) will work for other than Cartesian coordinates.

This is not to take away from Rouben's exemplary coding skills, but for many novices, learning where the built-in tools lie can be useful.

## Hints for this cubic...

The attached worksheet gives some hints for using Maple to obtain answers for these questions about a one-parameter family of cubic equations.cubic.mw

## Approximately 9% if the jump at the disc...

The Gibbs phenomenon: near a jump discontinuity in f(x), every partial sum of the Fourier series for f(x) exhibits the Gibbs spike, which tends to approximately 9% of the jump in f(x).

Maple does not even have built-in tools for the Fourier series, let alone for the Gibbs phenomenon. See other posts on this forum for add-on packages for Fourier series. To my knowledge, none of these packages address the Gibbs phenomenon, but it's been a number of years since I wrote a series of articles on these packages for the Tips&Techniques column in the Maple Reporter. These articles can be found in the Application Center.

## Atomic Variables vs. Table entries...

You must have kept the default setting for the behavior of the underscore. In this default mode subscripted quantities become Atomic Variables. (Select "Atomic Variables" in the View menu to see all such in magenta.) The mess you are getting for the derivative of theta_sub_1 is because Maple is corrupting an Atomic Variable upon differentiation. If you made theta_sub_1 a table entry rather than an Atomic Variable, its derivative would be displayed with an overdot, just as it is on the x(t).

Given the setting you have for the underscore, when you subscript theta, press Control+Shift+minus. This will make theta_sub_1 an entry in a table whose name is theta, and the differentiation will be displayed properly. Of course, I'm assuming that there is no intrinsic reason why theta_sub_1 has to be Atomic, and that you are free to render it as a table entry.

## Resize the window?...

Yes, this has happened to me, and more than once. I believe the cure I apply is to resize the window, making it slightly larger or smaller.

## Round vs. square brackets...

If the input that creates equation (2) has square brackets as in [...], change them to round parentheses as in (...). Next time, upload a worksheet via the green up-arrow in the toolbar. The embedded image is much too small to see clearly what you did.

## The LUDecomposition command in the Linea...

You really don't want to calculate all the determinants needed for Cramer's rule. Instead, obtain the LU decomposition with the LUDecomposition command in the LinearAlgebra package.

## Are you typing 2D math in a document blo...

It would help to make the Marker column visible. Go to the View menu and select the option "Markers". A thin gray column will open at the left edge of the Maple workspace and yoiu will see in it pairs of opposing triangles. Each such pair delineates a document block in which you can enter typeset math if you are in math mode, or text, if you are in text mode. In math mode, 2D math will appear in a blue rectangle. If you right-click on this math, you will have the option of changing this executable math to non-executable math that will then be in a gray rectangle.

Somewhere in here is the reason why your 2D math is not executing.

## general vs. particular cases...

There are integrals for which a general result is obtained, but  which are not valid for particular values of a parameter such as n. These coefficients have to be evaluated with a separate integral for the particular values of n at stake.

At least one of the packages that users have created for generating Fourier series gets this right - the code identifies the special cases and determines the appropriate integral to obtain those coefficients. In fact, a recent thread on this forum dealt with at least two of those add-on packages.

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