Problem set 1 Due: Thursday, Sept. 17, 1998


1. Find all the real roots of x4+3x3-1=0. Can you find complex roots with your code? Show us how.


2. Calculate the first three positive roots of x = 2 tan x. This equation arises in calculating the exponential decay rates of certain modes of motions (called eigenmodes) of an incompressible viscous fluid contained between two long parallel walls.


3. Compute as we did in class but this time using a series of ever finer polygons on the outside of the circle. Your algorithm should be numerically stable, we do not want to have the catastrophic roundoff error problems that we experienced in class!



Fabian Waleffe
1998-09-10