Recent content by ksuer

Any hint? Thanks!

I tried at some point on the curve, the gravity force goes down, then use 2nd Newton law. Thus, P = ma = my''. But, P = mg. It does not seem right and I can't find the relation y and x.

Homework Statement [PLAIN]http://vctson.com/temp/curve.jpeg Find the curve y = f(x) so that the ball travels from A to B in minimum time? Thanks!

Problem: find number of roots of z^n + a_{n-1}z^{n-1} + ... + a_0, |z| < 1 What is wrong with this argument: Let f(z) = z^n + a_{n-1}z^{n-1} + \cdots + a_0, and g(z) = - a_{n-1}z^{n-1} - ... - a_0. Then, |f| > |g| and f+g = z^n. by Rouche thm, number of roots of f is equal to number of roots...