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Selected answers to common questions:
- Left Associativity [05/27/1999]
Is the 'left to right' rule in mathematics a law or is it just used for
- Limit of Cos(Cos( ... Cos(x) ... ))) [02/24/2001]
Find the limit of a repeating trigonometric expression cos(cos( ...
cos(x) ... )) as the number of cosines goes to infinity.
- Mapping 3D Line Segments [10/06/1997]
How do I map 3D line segments onto a 2D perspective as seen from an
arbitrary point in space?
- Math in Computer History [11/04/2000]
I'm doing a major project on the history of computers, focusing on the
mathematical issues and ideas. Can you list some math topics and the
names of some key mathematicians who were involved?
- Math Tutorials [11/15/1995]
Windows-based tutorials for high school and college level algebra.
- Matrices and TI Calculators [03/06/1997]
How do I solve a set of three equations in three unknowns using matrices
on my TI-82 calculator?
- Meaning of Second Derivative Notation [07/08/2004]
What does the second derivative notation, (d^2y)/(dx^2), really mean?
I'm confused by the x^2 in the denominator.
- Mod Function and Negative Numbers [04/28/2000]
What is the correct value for the function MOD(-340,60)? Microsoft Excel
returns the value 20, while Lotus 1-2-3 returns the value -40. Can you
explain the difference?
- Modulus algebra: c = ( m * x ) mod p [03/14/2003]
Can anybody tell me an efficient algorithm or solving method to solve
the following problem written in Java?
- Monte Carlo Method and Computer Simulation [04/04/2002]
What is the Monte Carlo method? I know it's for estimating
probability, but what is the point of it?
- Multiplicative Inverse in Finite Field GF(2^8) [02/23/2005]
Is the multiplicative inverse of a 4x4 matrix in GF(2^8) the same as
the inverse of any 4x4 matrix?
- Multiplying and Dividing Computer Style [09/08/1998]
How does a computer multiply and divide?
- My Calculator Gives Wrong Answers for Large Values of x ... [01/20/2010]
Doctor Vogler reveals how a calculator's imprecision leads to
increasingly large rounding errors -- and misleads a student trying to
make sense of the formula for the base of natural logarithms.
- Negative Numbers in Base 2, 16, etc. [01/24/2003]
Are there negative numbers in alternate bases? Our calculator says
that 1-2 in base16 is FFFFFFFFFF. This can't be right!
- Negative Numbers in Binary [08/19/1999]
How do I represent -53 as a binary number? Is it 110101? Wouldn't that be
- Non-Linear Equations and Chaotic Systems [03/21/2002]
Are any non-linear equations used to predict complex or chaotic systems
such as traffic or flocking birds?
- Numeric Derivatives Using TI-83, TI-92 [10/17/2003]
My calculator says that the numeric derivative of sin(x) is
sin(2x)/(2x). Shouldn't it be cos(x)?
- Operator Precedence [08/13/2003]
Since the following statement is true: (1+1)**(5-2) is 8, why is the
following statement true and not false: 2**1+1 is 3 and not 4, and
3*1**3 is 3 and not 27...' ?
- Order of Operations [05/19/1999]
Given a, b, x, and y, find ax/by.
- Order of Operations and Negation in Excel [01/13/2000]
A discussion of why Excel evaluates an expression like -3^2 as (-3)^2
and a look at the mathematical conventions behind the confusion.
- Pane Rotation - Computer Graphics [11/14/1996]
How do I find a formula for rotating a pane in space?
- Parity Check [11/12/2000]
What is a parity check, and how does it work?
- Pascal Calendar Program [02/12/2002]
Holiday homework: make a program in Pascal that with a date of our choice
give us the day of the week.
- Perfect Number Algorithm [10/24/2001]
I'm having trouble creating an algorithm to test whether or not a number
is a Perfect Number. I'm trying to find one that would be easily
translatable into C++ code.
- The Perimeter of an Ellipse or Oval [9/5/1996]
What is the formula for calculating the perimeter of an oval, or an
- Piecewise Functions on TI Graphing Calculators [02/08/2005]
I was wondering if you could tell me how to graph a piecewise function
on a TI-83 plus graphing calculator?
- Planar Approximation: Latitude and Longitude [04/18/2003]
I am trying to calculate the midpoint between cases of legionella and
their nearest neighbor. How can I calculate the distance between two
points below which they can be treated as if they were in a plane
rather than on a sphere?
- Primality Test [11/26/2001]
I want to write a program using Pascal that will verify whether a number
- Prime Factoring Large Numbers [03/28/2003]
What are the prime factors of 5515596313?
- Prime Factors, Modular Arithmetic, and Using Pari [08/08/2007]
Suppose we have two positive integers 'a' and 'b'. Is there a method
to find a positive integer 'k', such that a + bk = x^2 for some
integer 'x'? In other words, how can we find a positive integer 'k',
such that 'a + bk' is a square?
- Probability and the Prisoner Problem [07/04/2001]
Each of 16 prisoners receives a hat that is either red or blue (the
colour is selected randomly; each has a 1/2 probability). All the
prisoners must simultaneously either try to guess the colour of their
hats, or pass.
- Programming the Distance Formula [03/26/2001]
I want to write a computer program to find the point on a line that's a
distance X from a given point not on the line. Can you help?
- Program to Calculate Pi [05/23/1997]
I am trying to write a program on my TI-83 calculator to calculate the
infinite digits of Pi while displaying them on-screen.
- A Program to Compute Pi [06/09/1999]
Can you tell me a good algorithm to calculate pi? I want to calculate pi
as exactly as possible with more than 1000 figures.
- Program to Find N-digits of Pi [9/11/1996]
I am writing C code to find the first N digits of pi, but I am limited by
the number of digits that C's built-in types can store.
- A Quick Overview of P vs. NP Problems [11/19/2007]
Can you explain what P and NP problems are at a level that a high
school student can understand?
- Radius, Center of Circle Given 3 Points [8/28/1996]
What is an easy formula to calculate the center point and radius of a
circle given three points on the circumference?
- Random and Pseudorandom Numbers [10/13/1998]
When are the numbers of a sequence truly random numbers and not
- Recommended Algebra Software [7/23/1996]
I am looking for math software programs with a focus on algebra.
- Remaining Confusion [09/10/2011]
A programming student wonders where she has gone wrong interpreting modulus
among the order of operations. Doctor Peterson shows how to proceed, offering up
three ways to evaluate the remainder, before anticipating (correctly, it turns out) where
the student might have erred.