Investigate the parameters A and B to see how they effect the functions y = Asin(Bx), y = Acos(Bx), y = Atan(Bx), y = Asec(Bx), y = Acsc(Bx), y = Acot(Bx).
Explore Archimedes' method for approximating the value of pi by comparing the area of a regular polygon to the area of the corresponding circumscribed circle.
This aplet contains sets of bivariate data which have the same summary statistics but totally different 'shapes' when graphed. They illustrate the need to rely on more than just the stats when deciding on whether a linear model is appropriate!
The program performs calculations of angles, distances, area and volumes of any figure. It can draw figures and keeps the points for possible modifications or calculations.
One of the most fundamental theorems in the study of statistical inference is the Central Limits Theorem. This states basically that the means of successive random samples taken from a population will be normally distributed whatever the underlying parent distribution. This aplet illustrates this and that the standard deviations are related by ratio. Sampling can be done from different parent distributions and the resulting collection of means compared to the equivalent Normal distribution. It is fairly slow to execute because of the need for repeated sampling but would be quite useful to teachers.
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').
This aplet investigates the common charity game consisting of tossing of a coin onto a square grid. It requires only knowledge of quadratic functions and can be used at a number of levels: to illustrate the convergence of experimental values towards theoretical ones, to investigate fitting a quadratic curve to experimental data, and to introduce the idea of a probability function.
This aplet takes a vector problem involving two objects having an initial position and velocity and analyzes it as 'closest approach' style problem. A test tool rather than a teaching tool.
Investigate the polar form of the graphs of the conics to discover how changing the eccentricity and distance from the focus to the directrix effects the graph of the conic.
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.
This aplet uses visual methods to illustrate and introduce the Poisson distribution, through the sowing of dandelion seeds into a large patch of ground, which is then broken up into unit squares.
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 derivatives, 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.
This DoEasy-program shows you the Horner-Calculation of polynomial function-values. In case of f(x)=0 the program displays the factorized polynomial-function of the entered function. It's easier than it sounds like. View additional help for more information.
Explore points, slopes and equations of lines that enclose the figures. It is also possible for the student to investigate the piecewise functions that would create the exact drawing.
This program has four parts. One finds the F'(x), another graphs it, another finds it for values of x, and the last tells you what the current equation is so you don't have to enter it again.
This is a small financial program (it's only 1.4kb). You enter the principle, rate and time and the program returns the monthly payment, total amount that is paid and the total interest.
This library will add the built-in financial functions from the TI-83(+) to the HP-39/40g. This is only a Dutch version and this library is not finished yet! There is still lot to be done!
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.
This aplet calculates and displays measures of central tendency and spread for data which has been grouped into intervals. The user puts the interval mid-points into C1, the frequencies into C2 and the aplet will display the mean, proportional median, lower and upper quartiles and various other values. The user can also perform calculations such as finding the values which cut off the top 15% of data, the middle 30% etc.
This is a lite version of the library originally developed by Martin Lang, includeing a hexadecimal and a binary calculator, two percentage functions and an alpha lock utility. Written in System RPL.
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 problems. It will then tell them if they are right or wrong, offering a second chance if needed.
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.
This aplet uses a statistical model to simulate a person trying to find one particular key of six in their pocket. A investigation into the average run length when throwing dice.
Identify the slope and the y-intercept given a linear equation, and will describe the various effects positive, negative and zero values have on the graph.
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.
The student nominates what they think is the line of best fit for a set of bivariate data. They can then adjust the line interactively, seeing the effect on the sum of squares of residuals.
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 bit slow but the result is very impressive. It's a wonderful tool for teachers marking test papers - it lets you easily check whether a student's feasible region is correct if they have their constraints wrong. That's why I orginally wrote it: sheer frustration after the 20th paper that had to be reworked from scratch to assign part marks.
School activity designed to investigate the visual representation of the iterative process, and the effects on the iterative process of choosing "unstable" initial values.
Group of number theory programs for modulo powering, prime testing and factorizing of integers. Includes Rabin-Miller test and Shanks square form factorization. Full documentation in German.
Explore the four different parameters that effect the graph of y=Asin(BX+C)+D and/or y=Acos(BX+C)+D, and will be able to analyze these symbolically and graphically.
An essential tool for any student going into an exam which involves probability functions. This is two copies of the Solve aplet with equations pre-entered for Discrete and Continuous probability density functions respectively. Covers the Binomial distribution (individual and cumulative), the Poisson distribution (individual and cumulative), the Exponential function, the Normal distribution, plus more.
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.
Investigate the effects of changing A, H, and K in the vertex form of a quadratic function. Analyze the effect of these parameters symbolically and graphically.
This is a collection of programs that help you with quadratic equations. At the moment there are programs to find x-intercept, axis of symmetry and the turning point.
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.
This aplet which gives the user drill in rounding to a number of decimal places or to a number of significant figures. This is purely a drill program not a teaching aplet.
School activity designed to investigate the use of elementary row operations in the reduction and/or solution of a 3 by 3 system of linear equations expressed as an augmented matrix.
School activity designed to simulate sets of observations on various discrete and continuous random variables. These can be used in test problems or exercises, or as aids in teaching the topic of random variables.
School activity designed to investigate the definitions of sine, cosine and tangent on the Unit circle. These can be used in test problems or exercises, or as aids in teaching the topic of random variables.
School activity designed to investigate the production of a field of slopes from a derivative function stored in F1(X), and the drawing of multiple possible integrals given starting points (x,y).
A complete statistics package for the 39/40G. Does Chi^2, F-tests, ANOVA, binomial, geometric, Poisson, normal probability plots, residual calculation, a whole lot of simulations, and a whole lot more. Has built in help for all commands in the NOTE.
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.
School activity designed to investigate a problem in optimization where they are required to maximize the volume or minimize the surface area by manipulating a single variable.
Get the tangent to a function given in F1(x) in a point you choose. It will be written in F2(x) so you can watch it in the plot view. Really interesting!
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.
School activity designed to easily and quickly analyze Time Series style data, by calculating moving averages (3, 4 and 5 point), seasonal residuals, trend lines and seasonally adjusted data. It more a working tool, rather than an investigative tool.
This is an easy adaption of the Parametric aplet which allows the student to investigate geometric transformations using 2x2 matrices. It is a fantastic teaching tool - my class deduced all the basic 2x2 transformation matrices for themselves in less than an hour.
This aplet does closest approach problems (including showing full working) in 2D and 3D as well as dot products and division of vectors in a given ratio. There are also two other programs which are not part of the aplet but are worth looking at.
School activity designed to investigate the relationship between the position, velocity and acceleration vectors for functions defined in the form (x(t),y(t)).