Truman State Mathematics and Computer Science Student Newsletter

November 16-30, 2009

Upcoming Events:

The SMACS scholarship program is sponsoring a guest speaker Monday, Nov. 16 at 7pm in VH 1328.  John Haney, a former math/CS double major from Truman, will be our guest speaker.  His work biography is as follows: 

John Haney graduated from Truman in 2001 and worked for Motorola for 7 years creating high-performance multithreaded network test software.  In 2008, he took the leap to video game programming for Chewy Software, working on 7 titles released in retail stores.  He created the Flashlight app for iPhone which has reached 11.5 million downloads.  He has recently joined Sears Holdings Corporation developing iPhone apps as a Mobile/Innovation Developer.

There will be an MCS Colloquium on Tuesday, November 17th at 3:30pm in VH 1236.  Dr. Kenneth Price from the University of Wisconsin at Oshkosh will present Matrix Structures from Directed Graphs.  Cookies and Refreshments!

MAA will be having a meeting in the Student Organization Room (2nd floor of VH by MTCS office) Tuesday, November 17th at 6:30 pm.

TWICS (Tru-Women in Computer Science) will be meeting Mondays from 5:30-6:30pm in VH1208.
SATSU (Society of Actuaries at Truman State University) meets from 6:00-6:30PM every Monday in the Student Organizations Room (outside math dept. office). For more info email: actuary@truman.edu OR Become a Fan of Satsu on Facebook!

Announcements:

The American Mathematical Society offers Headlines & Deadlines for Students, providing email notification of mathematics news and of upcoming deadlines that are of special interest to both graduate and undergraduate students. These email notifications will be issued about once a month, and when there's special news. Imminent deadlines will be included in these emails, which will link to a web page that's a centralized source for information relevant to students and faculty advisors, at http://www.ams.org/news-for-students/.

 

Please submit any announcements for the next newsletter to Dr. Dana Vazzana at dvazzana@truman.edu  by Monday of each week at noon.

 

If you are not on the email list for math majors or CS majors and you would like to be on one of these, contact Dr. Don Bindner at dbindner@truman.edu to be added.  Be sure to specify math, CS, or both.

 

Problem of the Week:

PROBLEM:  Let a 2 x 3 grid be given, with the first row numbered 1, 2, 3, and the second row numbered 4, 5, 6.   Two operations on the grid are allowed.  One operation rotates the left 2 x 2 sub-grid 90 degrees clockwise, that is, it sends 1->2->5->4->1.  The other operation rotates the right 2x2 sub-grid 90 degrees clockwise, that is, it sends 2->3->6->5->2.  Given any successive applications of these two operations, how many different permutations of the grid can result?  What is the group of these permutations?

Solutions should be submitted to Dr. Marty Erickson at erickson@truman.edu by Sunday,  November 29 at noon.

No correct solutions to the previous problem were received.  Dr. Erickson's solution is below:

PROBLEM:   What is the locus of points P in the plane such that there are two perpendicular tangents from P to the parabola y=kx^2 ?

Solution:  Let a tangent to the parabola be y=mx+n.  Since mx+n=kx^2 has a double root, we have by the quadratic formula m^2+4kn=0.  Suppose that the tangent passes through the point (x_0,y_0) on the parabola.  Then y=mx_0+n, and hence m^2-4kmx_0+4ky_0=0.   Since the two tangents are perpendicular, the two roots m_1 and m_2 satisfy m_1m_2=-1, and therefore the locus is y_0=-1/(4k), a horizontal line.