View Proposal #144

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ID144
First NameDave L.
Last NameRenfro
InstitutionACT Inc.
Speaker Categoryother
Title of TalkThe Remarkable Equation tan(x) = x
AbstractAlthough tan(x) = x is virtually the prototypical example for solving an equation by graphical methods, and this equation frequently appears in calculus texts as an example of Newton's method, there seems to be nothing in the literature that surveys what is known about its solutions. In this talk I will look at some appearances of this equation in elementary calculus, some appearances of this equation in more advanced areas (quantum mechanics, heat conduction, etc.), the fact that this equation has no nonreal solutions and that all of its nonzero solutions are transcendental, and some curious infinite sums involving its solutions. In addition, I will discuss some of the history behind this equation, including contributions by Euler (1748), Fourier (1807), Cauchy (1827), and Rayleigh (1874, 1877).
Subject area(s)transcendental equations
Suitable for undergraduates?Yes
Day Preference
Computer Needed?
Bringing a laptop?N
Overhead Needed?Y
Software requestsNo
Special NeedsNone
Date Submitted3/27/2006
Year2006