The Math Major Vol. 2, No. 5

The Math Major

CSU Fresno Mathematics Department

Vol 2. No. 5

Editor: Dr. Larry Cusick.

Spring Math Courses

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. Next week: math 107, 108, 110, 123, 151, 171 and 252.

Math Alliance News--Chess Tournament

(From Dr. Velasquez) The Math Alliance is planning a chess tournament. The date is still unknown, but could be as soon as in one or two weeks. Contact Dr. Velasquez for more information.

Graduate Assistants for Spring Semester

If you are interested in a Graduate Assistant position for this Spring semester, contact the department office as soon as possible.

Reminder: The Proof on TV

Don't forget about the NOVA broadcast of The Proof --The drama behind Andrew Wiles' proof of Fermat's Last Theorem. This will be shown on local channel 18 (PBS) on Tuesday October 28 at 7 p.m.

Problem Corner

Problem 2.4: The letters a, b and c represent different digits, a is a prime, and a-b = 4. If the number aaabbbc is a prime, find the values of a, b and c.

Solution to Problem 2.4: The test for divisibility by 3 shows that 3a+3b + c must not be a multiple of 3; therefore c \= 0, 3 or 9. Also, for the number to be prime, c \= 2, 4, 5, 6 or 8. Therefore c = 1 or 7. The test for divisibility by 11 shows that

(2a + b + c)-(2b + a) = (a-b) + c = 4+c

must not be a multiple of 11. Therefore c \= 7, so c = 1. Since a-b = 4 and a is prime we can only have have (a, b) = (5, 1) or (a, b) = (7, 3). Since c = 1, the answer is (a, b, c) = (7, 3, 1). The number 7,773,331 is a prime number.

Correct solutions were received from Anar Ahmedov, John Jamison and Lina Obeid.

New Problem

Problem 2.5: (Due no later than Thursday November 6, 4pm) 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.

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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