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Selected answers to common questions:
Composition of functions.
Domain and range.
Inverse of a function.
- Undefined and Indeterminable ... at the Same Time? [09/05/2010]
A student wonders whether the labels "undefined" and "indeterminate form" could
apply to one and the same expression. Doctor Vogler considers several expressions,
functions, and limits to distinguish the different contexts that call for such terminology.
- Unraveling an Inverse Function [11/30/2001]
I got this question wrong: y = (-5x - 2) / (-x + 1).
- Using Phase Shifts to Modify a Sine Curve [06/30/2005]
What modifiers can be used to fatten a sine wave while not affecting
the zeros and peaks?
- The Vertical Line Test for Functions [05/06/2004]
I'm having a problem understanding functions. I understand that for
every "x" there must be only one "y". But the vertical line test is
what is confusing me. Can you explain it to me?
- Walsh Spectra [03/07/2002]
What are Walsh spectra?
- What are Piecewise Functions? [05/13/2001]
I know piecewise functions are based on expressions between specific
intervals, but I do not know how to describe this function family.
- What is a Functional Transformation? [08/11/2002]
I would like a brief definition of a functional transformation and
what an application is in early Calculus.
- What is the Gamma Function? What is Gamma of 4? [05/28/1998]
Deriving G(4) = 3! from the gamma function integral.
- When Can Two Functions Be Inverses in Only One Direction? [09/28/2005]
If f and g are functions and f(g(x)) = x but g(f(x)) does NOT = x,
then what are f and g?
- Which Piece of a Piecewise Function? [09/05/2003]
Given a piecewise function, how do you know which piece to use to
compute a function value?
- Why Are Functions Important? [02/03/2005]
Why does it matter if something is a function or not?
- Why Can't Some Functions be Integrated? [11/06/1996]
How do I evaluate Integral[x tanx dx]?
- Why Do Recursive Rational Functions Attract and Repel? [07/10/2008]
Given a recursive linear rational polynomial with two roots, if you
recursively apply f(x) the function will converge to one of the roots.
Why does the function have a preference to one of the roots? How can
you determine the attractor root other than trial and error?
- Why Do We Have Functions? [04/01/2003]
Why do we have functions? Why do we have things like (g(x) = x + 3,
find g[f(2)] ?
- Why use f(x)? [02/14/1999]
Why use f(x) in an equation instead of y?
- The Wrapping Function, Unravelled [06/29/2012]
A student has questions about the wrapping function. After clarifying its three
variables, Doctor Peterson offers several ways to think about this spiral, and visualize
- X^X^X^... = 2 [05/17/2000]
How can I solve x^x^x^... = 2 for x?
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