Miscellaneous Utilities
This page contains several utilities for my classes' and my own use. The utilities are written mostly in JavaScript and/or PHP; new ones will be added when needed and existing ones may be modified or removed without notice.
Please note that these utilities are provided "AS IS" without warranty of any kind, either expressed or implied, including but not limited to, the implied merchantability and fitness for a particular purpose. The entire risk as to the quality and performance of the utilities is with you.
Grade Calculator | Equation Solver | Text Converter | Back to Info Page | Index
Grade Calculator
This utility uses JavaScript to calculate the expected grades in Mathematics courses. Courses supported this Quarter: Math 152 and Math 50. Needless to say, the calculator is meant to be used in my classes only; if you are in someone else's class, please check with the instructor if (s)he plans to use the same grading method.
Usage: Just fill out the Web form below; make sure you select the correct course, as different courses usually have different grading scales. For past tests, homework and quizzes, enter the scores, separated by spaces; for future tests etc. enter the expected scores (the computer cannot predict your performance in the future, only you can (-: ). Then click on "My mark?" Repeat as many times as you like with different predicted scores (to do a "what if" analysis). An example is given below.
Example (Math 152): Suppose that you had 58 points on Midterm I, 65 points on Midterm II and your Homework/Quiz percentages so far were 80, 70, 100. You believe that your score on Midterm III will be 10 points higher than that on Midterm II and that on the Final Exam you will do 20 percent better than on Midterm II. You hope to get 100% on the remaining two quizzes (the four highest scores count!). You should enter Midterm scores as 58 65 65+10 , the Final score as 65*1.20*2 (no spaces in arithmetical expressions, please!) and the Quizzes as 80 70 100 100 100 . Try it; make sure that Math 152 is selected. The program will "tell" you that your expected grade is a "C+". Remember, that answer is only an estimate, not a promise!
Grade Calculator | Equation Solver | Text Converter | Back to Info Page | Index
Equation Solver
This utility is a simple application of the Intermediate Value Theorem (please see your textbook for details). It solves equations of the type
F(x) = 0 , where F(a)F(b) < 0 for some points a and b, and F is continuous on an interval containing a and b.
You have to supply F (in JavaScript notation; e.g. instead of "π" enter "Math.PI"; for the "sine" function use "Math.sin", for the natural logarithmic function type "Math.log" etc.) and the points a and b such that F(a)F(b) < 0 ; the program will find a point c between a and b such that F(c) = 0 . It uses the so-called Bisection Method, which is really just a well-organized multiple application of the Intermediate Value Theorem.
Example: Suppose that you want to solve the equation x³ – 3x + 1 = 0 The LHS of the equation can be entered as x*x*x-3*x+1 or as Math.pow(x,3)-3*x+1 . Using endpoints –2 , –1 we obtain the negative solution to this equation; for the two positive roots one can use 0 and 1 or 1 and 2. For comparison, the exact solutions are 2 cos(8π/9) , 2 sin(π/18) and 2 cos(2π/9) .
Grade Calculator | Equation Solver | Text Converter | Back to Info Page | Index
Text Converter
This utility converts the so-called backquote source text to regular Unicode (UTF-8 encoded) text. That way a regular US keyboard can be used to type a poem in, say, Czech or Bulgarian. Not all Greek, Cyrillic and/or Latin characters and necessary diacritical marks are currently supported, but things will improve (-: .
The utility is still in "β (beta)" and no help is available. However, you are welcome to play with it and use it to your heart's content (but see the Disclaimer at the beginning!).
Examples: The "backquote source text"
Za sutra`s`ni ru`cak: Ra`z`ni`ki i papri`cice u u`lu; `gevreci i
su`duk can be transformed into:
Зa cyтpaшњи pyчaк: Paжњићи и пaпpичицe y yљy; ђeвpeци и cyџyк.
It could also become Za sutrašnji ručak: Ražnjići i papričice u
ulju; đevreci i sudžuk if "Latinica" is selected.
Your friendly Math Instructor,
Miroslav D. Ašić