Problems and Contests (Math 394) --- Spring 2012
Do you enjoy solving problems? Do you like contests?

The undergraduate mathematics seminar on Problems and Contests may be for you. Come and participate when you can. For the Spring 2012 semester, we meet
Thursday,   2:10 – 3:00 pm,   in Math 306

Here is our first set of problems for the Spring 2012 semester.
  1. In a 100-yard race, Alex beat Bob by 10 yards and Bob beat Charlie by 20 yards. Assuming that each runner ran with a constant speed, by how much did Alex beat Charlie?
    This problem was part of UM's Lennes Competition in 2010.
  2. Suppose x0 = 3, x1 = 4, and the remainder of this sequence satisfies the recursion
    xn+1 = (xn−1)2 − n · xn
    Find an explicit expression for xn which is true for any integer n ≥ 1.
  3. Lines L1 and L2 are parallel while a different pair of lines L3 and L4 are also parallel. Point P moves so that the sum of its distances from the four lines is constant. Describe the path of P's motion.
  4. Can the following pattern be generalized? Are any two members of the sequence
    2 + 1,   22 + 1,   24 + 1,   28 + 1,   216 + 1,   etc.
    relatively prime?
  5. An envelope of a set of lines is a curve tangent to all of them. For positive number c, let Lc be the line with equation y = (2/c) + (1 − 1/c2) x. Find the envelope for this family of lines?

Last modified: 15 February 2012, Wednesday 13:07