Functns & Calc.
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   Chain  Rule
  Supplied along with a worksheet, this aplet encourages the student to deduce the Chain Rule for themselves via a series of pre-loaded examples.
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Author: Colin Croft

     
 
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    Chords
  This aplet uses chords of diminishing lengths to find the limiting gradient at a point. A worksheet leads the student into discovering differentiation. (Used to be called 'A Different Slant').
More Information Note: The 39/40G version is more efficient and slightly faster.

Author: Colin Croft

     
 
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    Christmas Trees
  This one is just for fun. A series of pre-defined graphs which look like Christmas trees, including one which is infinitely detailed near zero.  Could be good for a 'rainy day' exercise.
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Author: Colin Croft

     
 
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    Complete the Square
  This is a simple program written by a student which takes a quadratic in the form y = ax2+bx+c and converts it to y=a(x+h)2+v form. Because it is a program it should be downloaded into the Program Catalog.

Author: Grey Johnston

   
 
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    Complex Roots
  This shows the nth roots of a complex number on an argand diagram and gives their values in the forms a+bi and r cis theta.  This is a small program rather than an aplet and must be downloaded to the Program Catalog not to the Aplet Library.

Author: Andy Vella, Colin Croft

     
 
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    Curve Areas
  This aplet is ideal for use when first introducing the concepts of integration.  It uses upper and lower rectangles to find the areas under supplied curves. A worksheet then takes the student through the process of deducing the rules of integration.
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Note1:    This aplet has been updated to fix a bug.
Note2:    Updated again to make it smaller (slightly).
Note3:    Updated AGAIN to remove another small bug!
Note4:    Updated the documentation slightly (16 Nov 2000).

Author: Colin Croft

     
 
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    Curves Collection
  This collection of mathematical curves was originally hosted on Jim Donnelly's page but has been shifted to mine now that Jim has moved on to other interests. These apLets allow the user to explore interesting mathematical curves. Includes Cardiods, Catenaries, Astroids and Lissajous curves.  Excellent fun! Ideal for a maths enrichment class.

Author: Jim Donnelly

 
 
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    DFind/DSolve and QPrograms
  DFind/DSolve: This paired set of aplets, based around the Function and Solve aplets, allow the user to quickly and easily find the features of functions such as intercepts and extrema using derivitives, automatically finding the derivative functions as part of the process. Obviously this is something which can already be done with the Function aplet but these two aplets automate the process by switching automatically between the abilities of the Function and Solve aplets. As an examination tool it is definitely worth having. Note:  When you unzip this aplet and transfer it to the calculator you must be sure to download both aplets - DFind
Updated:  (24/3/02) A new version of DFind/DSolve has been posted which runs more efficiently.
Updated:  (7/4/02) Again another  newer version which has enhanced capabilities.
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QPrograms:
 This is an aplet which lets you perform a number of small tasks - calculate coefficients for binomial expansions, calculate mean and standard deviation of grouped data and divide complex numbers.
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These aplets were created by Matt Grosvenor, who is (in 2002) a final year student at Perth Modern School.  Matt only produced versions for the HP39G so HP38G users are out of luck in this case.  

Author: Matt Grosvenor

 
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    Function Deluxe
  This is a copy of the Function aplet with a vast number of extra features added via an amended VIEWS menu.  It appears to be very useful and I would recommend checking it out.

Author: Benjamin Kosta Pazolli <bpazolli@gmail.com>

     
 
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    Function 'Plus'
  This is a copy of the Function aplet with an extra entry on the VIEWS menu which produces 'nice' scales. You may have noticed that the default plot view scale of -6.5 to 6.5 produces 'nice' step sizes of 0.1 when using the trace facility.  This aplet will allow you to set whatever scale you choose and then correct it to the closest approximation which will still offer similar 'nice' trace values such as 0.2, 0.25, 2, 0.04 etc.  It includes the ability to produce scales which are 'nice' fractions of pi for use with trig functions.
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An alternative to this aplet is a program called Windfix (see below). This program can be used with any aplet and takes up less memory.

Author: Colin Croft

     
 
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    First 50, The
  This is a collection of small programs you can type in yourself or download.  They perform a multitude of small tasks, some that are so easy you'll wonder why I wrote a program for them, some that are really cool. For FAR more information click here.

Author: Colin Croft

     
 
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    Function 3D
  Version 1:
An aplet developed by Quin Pendragon (see below ) to graph three dimensional functions. Unfortunately it is very slow to produce its graphs due to the complexity of drawing 3D wireframes, but still quite interesting if you can do something else while it plots.
Note: I was recently informed that the 39G version crashes and so I've removed it.
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Version 2:
Another version, written in French by Yves Quemener. It looks good but I can't evaluate it because there's no documentation at all and I don't speak French. If anyone would like to compare the two and let me know which is better...
Version 3:
Another version, also written in French. The author, Hydreprod, informs me that it uses the F1 function the of the function Aplet. The user writes the function using the X and Y variables ( for example : f1(x)=1/x+1/y ) and then launches the aplet ('Start 3.d'). After being created, the image is stored in graphic variable G0 and can then be pasted into a sketch or used in a program.
This program manages:
  1. Isometric 3d
  2. Non-Isometric 3d (using the p.rate. 0=isometric)
  3. Undefined points, such as for example for the function 1/r with r=(x^2+y^2)^1/2
  4. Swing and slope angles
  5. An autoscale function (which is very slow).

In general the creation of an image takes between 5 and 6 minutes but the program can be modified to decrease the precision and so save time.
The link on the right will take you to the author's site.

 
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    GP Solver
  This aplet is simply a copy of the Solve aplet with the relevent equations for geometric progressions pre-loaded.  You can set it up easily yourself if you want to.
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Author: Colin Croft

     
 
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    Indices Practice
  This aplet provides simple drill practice for students learning the laws of indices, with the option of including negative powers.  It presents students with practice problems in correct mathematical layout and then allows them to enter the simplified answer. There are a wide variety of styles of problem. It will then tell them if they are right or wrong, offering a second chance if needed.
Updated 23/2/02: When the user gets it wrong the second time it will now display the correct answer, using positive indices and with cancelled fractions!  I'm very proud of this, so please check it out. :-)
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Author: Colin Croft

     
 
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    Inequalites
  This is a copy of the function aplet with the additional ability to graph inequalities (linear/non-linear) for F1, F2 and F3(X).  These can be overlaid to show intersections or unions.
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Author: Colin Croft

     
 
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    KeyDebounce
  The internal keybounce time is set in order to prevent a key registering twice.  When you press a key you may only hold it down for a fraction of a second but to the calculator this is a LONG time and if there were no delay set then it might, for example, read what you meant to be a '3' as a '33'.  However the default factory setting of 166.6ms delay is a little high and sometimes causes a REAL press of '33' to only register as a single '3' when you actually meant 33!  Changing the delay value to a setting of around 75ms will reduce the chance of this happening.

When you first run the aplet it will display the current delay time.  For an HP39G this is 166.6 milliseconds.  You can alter this to any value from 0 to 400.  Based on my experience a good value to try is somewhere around 100ms.

Once the value is set it will remain until a memory reset (ON+SK3 or ON+SK1+SK6) is performed on the calculator. Deleting the aplet will not affect it and, since the aplet is only 1.3Kb in size, it may be worth retaining.

Author: Detlef Mueller

   
 
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  Library L1542 (Version 1)
 
Released 8th July, 2003. This is an upgrade to the L1540 Library which also incorporates string handling. You need this if you're a serious programmer!!
Note: The included documentation is good but terse. I will be providing more detailed documentation when I have time. Check back later.

L1542 is a 33KB SysRPL library for the HP39/40. When you download it to your calculator this library gives access to an add-on collection of extra functions which then become available in HOME, in programs or in the CAS (on an HP40G). The functions essentially comprise much of what makes the difference between an HP40 and an HP49, plus some more.

Functions added include a decimal/hex conversions, a calendar, a list of metric/imperial conversions, a list of physical constants, some time/value/money functions similar to those on the TI89, probability functions, vector plot and matrix slope plot, multidimensional optimisation, discrete Fourier transforms and numerical solution of differential equations. Even a help command is included which explains how to use each function!

For programmers there are REALLY useful functions that let you do bit manipulations, perform graphic plots, call programs in nifty ways as functions (ie. returning values), use local variables instead of the global ones A..Z and, most importantly, input, manipulate and output string variables. String constants can also be realized with the aid of an additional tiny library L1840, which is included in this package.

   

This library even has a command to delete itself so that you don't have to reset your calculator (losing not only the library but everything else as well).

The source is included and compiles with the HP DOS tools.

Author: Martin Lang (Germany), with contributions from Jordi Hidalgo.

   

 
 
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    Linear Explorer
  An aplet similar to the Quadratic and Trig Explorers (but not as fast) which allows the student to explore linear graphs.  The equation of the graph is displayed at the top left corner of the screen and the student can change the gradient and y-intercept using the arrow keys.  Intercepts are shown on the screen.
Note: This aplet is one that I use as one of my example programs in the section on how to start programming on the HP. See the programming section of the Help page.

Author: Colin Croft

     
 
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    Linear Programming
  This aplet visually solves linear programming problems, finding the vertices of the feasible region and the max/min of an objective function. The final stage of finding the vertices is a very slow on an HP39G, but not too bad on a 39g+, and the result is very impressive. In the latest version you can also do sensitivity analysis on the solution you find. You can also edit constraints once they are entered which makes it a wonderful tool for teachers marking test papers - it lets you easily check whether a student's feasible region is correct if they have one or more of their constraints wrong. That's why I originally wrote it: sheer frustration after the 20th paper that had to be reworked from scratch to assign part marks. My students who had HP38Gs decided that it was not one of the aplets they would take into an exam because of its size but that won't matter on an HP39G or hp 39g+ and the new ability to do sensitivity analysis makes it essential.
More Information .
Note: Updated (6/8/99). Instead of discarding existing data every time the aplet is run, it now gives the option of retaining it.  This means you can exit the aplet, do something else and then re-run it without losing your constraints.
Note: Updated (8/8/04). Added sensitivity analysis to the aplet and the ability to edit constraints once entered. This makes it an essential tool for any student. (The 38G version was not updated.)
Note: Updated (16/8/04). Three small bugs fixed.
Note: Updated (20/8/05). Added the ability to delete constraints from the list rather than only edit them.

Author: Colin Croft

 

     
 
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    Newton-Raphson Iteration
  This aplet shows visually the process involved in the Newton-Raphson iteration. It is a useful aid both to teaching the topic and to illustrating instability based on starting points.
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Author: Colin Croft

     
 
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  Quadratic Explorer
  A wonderful aplet for investigating quadratic graphs in the form y = a(x+h)2 + c. A must for any student learning about these graphs. This is an HP aplet which I helped to design, written in machine code by Gerald Squelart (an HP programmer), and is fast and visually exciting.  It is built into the new HP39/40G.
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Author: Colin Croft, Jean-Yves Avenard for HP.

     
 
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    Root Finder
  This is a program not an aplet and must be downloaded into the Program Catalog.  If you give it the coefficients of a polynomial of any degree then it will give you the roots to any desired number of significant figures. If one or more of the roots are complex then it will ignore those and give only the real ones.

Author: Colin Croft

     
 
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   Root Finding (Advanced)
  This aplet was created by Roso Giuseppe (Beppe) and allows the user to perform some very advanced matrix operations. He says "I'm sending an aplet with my build of Newton-Raphson, bisections and secants
algorithms. A full explanation is supplied in pdf format. In my algorithms I show every calculus." 
Note: The 38G version will probably not become available.
     
 
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   RPN Simulator
  This program was created by Edward Shore to cleverly simulate Reverse Polish Notation on the calculator.  It's not as flexible as the real thing but for anyone wanting to find out why people enthuse over RPN, here's a chance to try it out.
Note: This is a program NOT an aplet and should be downloaded from the Program Catalog view not the Aplet view.
Author: Edward Shore <ews773@hotmail.com>
   
 
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   Simult 3x3
  One of the lacks on the HP has always been a quick and easy solver of simultaneous linear equations. This fantastic aplet, written in machine code for speed, fills in this hole perfectly.  Highly recommended.
Note:  On the hp 39g+ you MUST use the "Wire" option in the RECV menu to download this aplet, not the "Disk drive" option. When it pops up a window showing the files, choose "aplet.s". Otherwise the process is normal. On the hp 39gs/40gs, use the '39/40 USB' option.
Updated 28th Oct. 2003 - The solutions are now stored into variables X, Y and Z. This means that you can use them in the HOME view for later calculations, providing you don't over-write them. For example, using the PLOT screen over-writes X.

Author: MichaŽl De Coninck

   
 
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    Sine Define
  This aplet illustrates the production of the sine, cosine and tangent graphs from the unit circle. It includes a guided investigation looking at the 'squine' and 'cosquine' curves defined on a unit square instead of a unit circle.  Highly recommended.
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Note: This aplet has been updated (21/8/99). I fixed a bug caused by my having typed an 'O' instead of a '0' (zero).  I had also included a file in the ZIP file that didn't need to be there, so it's now smaller to download.

Author: Colin Croft

     
 
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    Slope Fields
  Given a function, this aplet will produce a slope field based on it. The user can then move the cursor to a point and draw the integral function through the field of slopes.  This is a difficult topic to teach well and this aplet is invaluable as an illustrative tool.
Updated 26th Feb. 2004 - The function F1(X) which supplies the derivative can now be a function of both X and Y. For example, F1(X)=X+Y is now permitted. Thank you to a user for the suggestion.
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Author: Colin Croft

     
 
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   Surd Simplifier
  This is a small but very handy program written by a student who obviously has some interesting ideas. If you enter a surd or an expression involving surds it will return the simplified version.

Author: Dale Shelton

Note: It is a program NOT an aplet, which means that you have to download it into the Program Catalog not the Aplet Library.
     
 
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    Sweets Box
  This aplet offers an introduction to the basic idea of calculus via the minimisation of surface area on a box with fixed volume. The solution is done via 'trial and adjustment'.
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Author: Colin Croft

     
 
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    Tangent Lines
  This aplet is basically a copy of the Function aplet with an additional ability to add a moving tangent line to a graph.  Three predefined functions are available, in addition to a user defined option.  The co-ordinates and the gradient are displayed at the top left corner of the screen as the tangent moves along the curve.
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Note: The 39/40G version is more efficient and slightly faster.

Author: Colin Croft

     
 
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Trig Explorer
  A wonderful aplet for investigating trigonometric graphs in the form y = a sin(bx + c) + d  or y = a cos(bx + c) + d . A must for any student learning about these graphs. This is an HP aplet which I helped to design, written in machine code by Cyrille de Brebisson (an HP programmer), and is fast and visually exciting.  It is built into the new HP39/40G.
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Author: Colin Croft, Cyrille de Brebisson for HP.

     
 
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   Ultimate Simplifier
 

This is a small program that takes a value you've found and tries to find an exact value for it, for example a surd or a fraction of pi or of e. If you've found your answer in Solve and need an exact value then this may be of use to you. This is a program not an aplet and should be downloaded to the Program Catalog.

Author: Alan Lark.

     
 
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    WindFix
  For those not wanting the full Function 'Plus' aplet (see above), this is a small program which does the same as the aplet but takes up less memory and will work with any aplet. For documentation, download Function 'Plus'. The difference is that this is a program instead of an aplet and hence is not run through the VIEWS menu.
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Author: Colin Croft

     
 
 
 

 

The programs below are an excellent collection of utilities and Notes written by Quin Pendragon, a former year 12 student at Helena College.  Some are better than others but most are highly useful.  Quin has grouped his programs into subject areas (for Western Australian subjects) and if you want to use them then you should download each ZIP file into its own directory. I have tried some of these but not all and I make no promises about them working OR giving the correct answers mathematically. If you have any problems let me know and I'll pass it on to Quin.
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Note:  Quin has chosen to write programs rather than ApLets.  This means that you need to load them from the Program Catalogue rather than from the LIB view.  Other than this the process is the same.  Programs take up less memory than ApLets but are a little less convenient to use. If you are thinking of doing something similar then be warned:  I don't put material on my page without documentation.
 
 
 
 
    Year 12 Applicable Mathematics
  A set of small programs written for the year 12 Applicable Mathematics course in Western Australia.  They may be of interest to other students whose courses contain similar topics.
Information
     
 
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    Year 12 Calculus
  A set of small programs written for the year 12 Calculus course in Western Australia.  They may be of interest to other students whose courses contain similar topics.
Information
     
 
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    Chemistry
  A set of small programs written for the Chemistry student in Western Australia.  Most Chemistry courses will overlap enough for them to be useful to other students.
Information
     
 
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    Physics
  A set of small programs for the Physics student in Western Australia.  Most Physics courses will overlap enough for them to be useful to other students.
Information
     
 
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    Games
  A series of small games for the calculator.  Because they are not written in machine code they are not fast and, not being a game enthusiast, I can't comment on their quality.  You can find information on them, including the controlling keys, here.      
 
 
 

Last modified: 19 Dec 2007                                             Sitemap        Home        Contact Me