The Math Major Vol. 2, No. 13

The Math Major

CSU Fresno Mathematics Department

Vol 2. No. 13

Editor: Dr. Larry Cusick.

Math Department Colloquia

Math Club Film Series

The Math Club sponsors a video film showing every other tuesday. Everyone is cordially invited to attend.

Seventeenth CSU, Fresno Math Field Day: A Success

On Saturday April 18, the CSUF math department hosted the Math Field Day for high schools. Students competed in competitions that required mathematical problem solving skills. The math department faculty would sincerely like to thank the CSU Fresno student volunteers and the staff of the department office who helped make the event possible.

A Mathematical Quote

"Who would not rather have the fame of Archimedes than that of his conqueror Marcellus?"

-- Sir William Rowan Hamilton (1805-1865)


Problem Corner

Problem 2.12: Prove that if a, b and c are distinct (no two the same) positive real numbers then a3 + b3 + c3> 3 abc.

Solution to Problem 2.12: Since a and b are unequal, (a-b)2 > 0, and so after expanding and rearranging gives a2 + b2 > 2 ab. Similarly, b2 + c2 > 2 b c. Adding and dividing by 2, a2 + b2 + c2 > ab + bc + ac. Multiplying both terms of the inequality by a+b + c, and omitting the terms common to both, we have a3 + b3 + c3 > 3abc.

There was only one solution turned in, and it was incorrect.

New Problem

Problem 2.13: (Due Thursday April 30 by 4 pm) Fold an 8 inch by 11 inch piece of paper in such a way that a pair of diametrically opposed corners touch. What is the ratio of the respective lengths of the fold line to a diagonal?

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.