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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.
- Repeated Square Roots and Logarithms [04/05/2005]
A discussion based on a calculator trick where taking 'n' repeated
square roots of 'a', then subtracting 1 and multiplying by 'b', then
adding 1 and squaring 'n' times, leads to a result very close to a^b.
The explanation is closely related to logarithms.