The Math Major Vol. 2, No. 6

The Math Major

CSU Fresno Mathematics Department

Vol 2. No. 6

Editor: Dr. Larry Cusick.

Spring Math Courses Part II

The math department will offer 12 upper division and 3 graduate level mathematics courses this spring. In this issue and the next you will find a short description of each in the words of the instructor who will teach the course.

Video Presentation: The Proof

Thursday, November 13, 3:10-4:00 p.m. San Ramon 6, Room 6. This video documentary film covers some of the history and flavor of Andrew Wiles' proof of the famous conjecture known as Fermat's Last Theorem. Many mathematicians in the last 350 years have tried to prove or disprove Fermat's Last Theorem, which is that xn+yn=zn has no positive integer solutions for n>2. The video is not a technical descripition of the proof itself, which is very complex, but instead describes some of the personalities, interactions and emotions felt by those involved in completing the proof. Free popcorn and soda!

Problem Corner

Problem 2.5: In the semi-circle shown, diameter P0P1 = 2. Angle P0P1P2 = 1 degree; angle P1P2P3 = 2 degrees; angle P2P3P4 = 3 degrees; ..., Pk-1PkPk+1 = k degrees. If PkPk+1 is the first chord whose length is less than 1, compute k.

Solution to Problem 2.5: Since the radius is 1, a 60 degrees arc is subtended by a chord of length 1. Therefore we are looking for the first chord whose arc is less than 60 degrees. Minor arc P1P2 = 180 - 2; in degrees minor arc P2P3 = 180 - (2+4) = 180 - 2(1+2). In general minor arc PkPk+1 = 180 -2 (1 + 2 + 3 + ... +k) = 180 - 2 k(k+1)/2 < 60, which implies that k(k+1)> 120, so k = 11.

Correct solutions were received from Anar Ahmedov and John Jamison.

New Problem

Problem 2.5: (Due no later than Thursday November 20, 4pm) There are several values for a prime, p, with the property that any five digit multiple, m, of p remains a multiple of p under every cyclic permutation of the digits of m. One such value is p = 41 (for example, 50635 is a multiple of 41, so are 55063, 35506, 63550 and [0]6355). Another such value of p is 3. Compute the value of p that is greater than 41.

Solutions may be delivered to the math department office (for Dr. Cusick) or by e-mail at larryc@csufresno.edu. There is a $75 dollar first prize and a $50 second prize to be awarded at the end of the semester to the student(s) who submit the most correct solutions.


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