Problems for next lecture (+ bring your exam dates!)

First, for administrative purposes:
The schedule for the end of the semester is not completely settled. Can you all check your exam dates (resolving possible time conflicts with other ECON courses will be given priority!) til next lecture?

Then, problems for you, to be covered in lecture:

1. I did state that a quasiconcave and homogeneous function is concave provided the index of homogeneity is in (0,1]. Use this to show that ||x|| is convex.
2. Use the same result to decide for what parameters the CES function is concave
3. As posted yesterday, correct my mistake on the board.