Programming Your Calculator Casio fx-7400G PLUS Barry Kissane
Programming Your Calculator: Casio fx-7400G PLUS Published by Shriro Australia Pty Limited 72-74 Gibbes Street, Chatswood NSW 2067, Australia A.C.N. 002 386 129 Telephone: 02 9370 9277 Facsimile: 02 9417 8957 Email: casio.edusupport@shriro.com.au Internet: http://www.school.casio.com.au Copyright © 2000 Barry Kissane All rights reserved.
Barry Kissane INTRODUCTION The Casio fx-7400G PLUS does not have all the capabilities of larger, more sophisticated (and considerably more expensive) graphics calculators. This booklet contains examples of programs that you can use to extend its capabilities in various ways. Some of the programs allow the calculator to undertake tasks usually available only on more sophisticated calculators (such as solving equations).
Programming your calculator commands that are used almost exclusively for programming. These are accessed by first accessing ( ). The inside back cover of the User's Guide shows where all programming commands are, while Chapter 8 describes in detail how each command works. When you have finished entering the program into the calculator, press to return to the programming list menu. Test the program to make sure there are no typing errors.
Barry Kissane Deleting programs Programs remain in your calculator until you delete them. They are not affected by turning the calculator off. To permanently delete a program, go to the program list with , and press the continuation key. Use and to select the program name from the list, and then press ( ). To delete all the programs in a calculator, choose . ( ) instead of ( ).
Programming your calculator I express my gratitude to Debbie Taylor, who has been encouraging during this project and especially helpful in checking the text and the programs in this book, although I remain responsible for any lingering errors that you may find. I hope that you enjoy using these programs and wish you well in starting the adventure of writing some others for yourself or your friends.
Barry Kissane INDEX OF PROGRAMS Page Calendar ..............................................................................................1 Heron.....................................................................................................2 Zero........................................................................................................3 2 x 2 EQ.................................................................................................4 3 x 3 EQ....................................
Programming your calculator
Barry Kissane CALENDAR Purpose Gives the week day for any date, according to the Gregorian calendar, which is in everyday use today in western countries. The program evaluates a formula that takes leap years appropriately into account. Operation Enter the day, month number and year (all four digits), pressing example, 31 August 1949 is entered as . after each. For Important Note: January and February must be entered as the 13th and 14th months of the previous year.
Programming your calculator HERON Purpose Uses the lengths of the three sides of a triangle to calculate the area of any triangle, using Heron's formula, known since ancient times. Operation Enter the length of each side, followed by √2) are permitted. . Both numbers and expressions (such as The program displays the area of the triangle. Press to enter the side lengths of another triangle.
Barry Kissane ZERO Purpose The program finds approximately a zero of a function, i.e. a value of the variable for which the function has zero value. Operation The function must be entered as in the function list and then graphed. Trace to a point near a zero you want to find and then activate the program. The coordinates of a point close to the zero are given as a list. The first element is the zero itself (the x-value).
Programming your calculator 2 X 2 EQ Purpose Solving a set of two simultaneous linear equations, by entering only the coefficients of each. Operation The program reminds you of the form for the equations: a11 x + a12 y = b1 a21 x + a22 y = b2 You may have to rewrite your equations into this form before entering them. Input the six coefficients in the correct order, pressing after each. If the coefficients are all integers, the result will be given as a fraction.
Barry Kissane 3 X 3 EQ Purpose Solving a set of three simultaneous linear equations, by entering only the coefficients of each. Operation The program reminds you of the form for the equations: a11 x + a12 y + a13 z = b1 a21 x + a22 y + a23 z = b2 a31 x + a32 y + a33 z = b3 You may have to rewrite your equations into this form before entering them. Input the twelve coefficients in the correct order, pressing after each. If the coefficients are all integers, the result will be given as a fraction.
Programming your calculator QUADEQTN Purpose Finding the roots of a quadratic equation, using the quadratic formula. Operation The program reminds you of the form of the equation: ax2 + bx + c = 0. You may have to rewrite your equations into this form before entering them. Input the three coefficients in the correct order, pressing after each.
Barry Kissane INTRSECT Purpose To find the coordinates of a point of intersection of the graphs of two functions. This can be used to solve a pair of simultaneous equations. Operation Start by graphing the two functions, using Y1 and Y2. Trace to a point close to the point of intersection. Then activate the program. The result will be given correct to three decimal places. The program reminds you that the two functions must be in Y1 and Y2.
Programming your calculator MINIMUM Purpose Find the coordinates of a relative minimum of a function. Operation The function must be in Y1 in the list. Draw a graph of the function and trace to a point near a minimum point. Activate the program, which will give the coordinates of the minimum point, correct to three decimal places. Test the program by finding the relative minimum of the function y = x2 – x – 1. The result is (0.500,-1.250).
Barry Kissane MAXIMUM Purpose Find the coordinates of a relative maximum of a function. Operation The function must be in Y1 in the list. Draw a graph of the function and trace to a point near a maximum point. Activate the program, which will give the coordinates of the maximum point, correct to three decimal places. Test the program by finding the relative maximum of the function y = x3 – x – 1. The result is (-0.577,-0.664).
Programming your calculator SEARCH Purpose To search systematically through a range of values in order to solve a problem. Operation In its present form, the program checks each of the numbers from 10 to 100 in turn to see whether any of them satisfy the following condition: The product of the tens and units digit, added to the sum of the tens and units digit, gives the original number. When the program is run, any numbers satisfying the condition are printed. Press to continue after each answer.
Barry Kissane INTEGRAL Purpose To find the area under a curve and above the x-axis between two points, using the integral of a function. Operation The program reminds you that the function must be in Y1. Enter the function in Graph mode and then start the program in Program mode. Enter the x-value for the lower limit and the upper limit, pressing after each. The area is then printed on the screen. To test the program, check that the area under the function y = 1 – x2 between x = 0 and x = 1 is 0.785.
Programming your calculator DECIMAL Purpose To give the decimal expansion of a fraction to as many decimal places as desired. Operation Enter the numerator and the denominator, both whole numbers, pressing each. after Each time you press , the next digit in the decimal expansion will be given. Record these on paper if you wish. Note that the decimal point is not displayed by the calculator. Press ON when you wish to stop. To test the program, check that the decimal expansion of 3/13 is 0.023076923..
Barry Kissane FACTORS Purpose To find all the prime factors of a positive integer. Operation Enter an integer at the prompt and press Each time you press to start. , another prime factor will be displayed. To test the program, enter 234 and check that the prime factors are 2 x 3 x 3 x 13.
Programming your calculator DICE Purpose To simulate rolling a standard six-sided die, for which each of the six possible scores are equally likely. Operation Enter the number of rolls required. (The maximum is 255.) Press to start. The program will display the mean score of the simulated dice rolls. The actual rolls are stored in List 1. Any data already in List 1 will be lost. Press Menu 2 to see the data, and to analyse them if you wish.
Barry Kissane TWODICE Purpose To simulate rolling two standard six-sided die, for which each of the six possible scores are equally likely on each die. The two die rolls are added each time to produce a score. Operation Enter the number of rolls required. (The maximum is 255.) The program will display the mean score of the simulated dice rolls. The actual totals are stored in List 1. Any data already in List 1 will be lost. Press Menu 2 to see the data, and to analyse them if you wish.
Programming your calculator COIN Purpose Simulate tossing a coin and counting how often a head is obtained. Operation Enter the (whole) number of tosses. There is no limit on the number, except your time and batteries. With fresh batteries, the calculator will need about 30 seconds for each thousand tosses. The program will display how many of the tosses were 'heads'. Do this a few times to see how much it varies each time. Compare your results with someone else's.
Barry Kissane FREQDIST Purpose To generate a frequency distribution from raw data. Operation The first two lines of the program remind you that the data must be in List 1 and must all be integers. Press to continue the program after the messages. The frequency distribution will be placed into Lists 2 and 3. Any data already in List 2 and List 3 will be lost. When finished, the calculator displays a message reminding you that List 2 shows the possible scores and List 3 shows the frequencies of each score.
Programming your calculator DIFFLIST Purpose Find the first and second differences for a sequence. Operation Delete the contents of List 1 and then enter your sequence into List 1. The program will store the first differences between elements of the sequence into List 2 and the second differences into List 3. Any data already in List 2 and List 3 will be lost. Press (or ) to see the results of finding the differences.
Barry Kissane LONGRUN Purpose To illustrate what happens in the long run when events with a certain probability are generated. For example, to see what happens when a fair coin is tossed repeatedly, by plotting the proportion of the heads after various numbers of tosses. Operation Enter the probability concerned and press to continue. The program will display the 'ideal' theoretical probability as a horizontal line. The vertical axis is marked in steps of 0.1 or 10%.
Programming your calculator SRANSAMP Purpose Take a simple random sample of a certain size from a population. A simple random sample is one for which each element of the population has the same chance of being chosen. Notice that it is possible for the same elements to be chosen more than once. (That is, sampling with replacement is involved.) Operation First delete the contents of List 1 and then enter the population of interest into List 1. (The population cannot exceed 255 elements.
Barry Kissane NORMAL Purpose To generate values for areas between two values of a normal probability distribution with mean M and standard deviation S. Operation Enter the mean and standard deviation, each followed by normal (z) distribution, enter M = 0 and S = 1.) . (For the standard Then enter the lower value and the upper value, each followed by . The probability that the normal random variable will have a value between these two is then printed, correct to four decimal places.
Programming your calculator BINOMIAL Purpose To simulate a binomial random variable, consisting of a number of trials each of which has the same probability of success. For example, tossing a set of 12 coins, each of which has a probability of 0.5 of landing 'heads', and counting how many of the twelve land heads each time. Operation Enter the probability of success each time, followed by Enter the number of trials involved, followed by . .
Barry Kissane BINPROB Purpose To generate values for the binomial and cumulative binomial probability distributions. Operation Enter the number of trials (N) and the probability of success for each (P), followed by in each case. The probability of zero successes is displayed on the screen. Write this result down on paper. Then press to see the probabilities of getting various numbers of successes, together with the associated cumulative probabilities. These are stored in List 1 and List 2 respectively.
Programming your calculator CMPNDINT Purpose To explore various compound interest situations involving a Principal, an Amount, an interest rate, a number of years of investment and a number of compounding periods per year. If all except one of these variables is known, the other one is calculated. Operation Enter the variable values when requested, pressing after each. Enter a negative value, such as -1, for the one value you wish to calculate. RATE P.A. refers to the annual interest rate.
