Category Archives: Teaching

High Dimensional Expanders: Introduction I

Alex Lubotzky and I  are running together a year long course at HU on High Dimensional Expanders. High dimensional expanders are simplical (and more general) cell complexes which generalize expander graphs. The course is taking place in Room 110 of the mathematics building on … Continue reading

Posted in Combinatorics, Teaching | 4 Comments

In how many ways you can chose a committee of three students from a class of ten students?

The renewed interest in this old post, reminded me of a more recent event: Question: In how many ways you can chose a committee of three students from a class of ten students? My expected answer: which is 120. Alternative … Continue reading

Posted in Mathematics to the rescue, Riddles, Teaching | 1 Comment

Test Your Intuition (11): Is it Rational to Insure a Toaster

Here is a question from last year’s exam in the course “Basic Ideas of Mathematics”:   You buy a toaster for 200 NIS ($50) and you are offered one year of insurance for 24 NIS ($6).   a) Is it … Continue reading

Posted in Probability, Rationality, Teaching, Test your intuition | Tagged , | 18 Comments

The Beauty of Mathematics

This semester I am teaching an introductory course in mathematics for students in other departments.  I taught a similar course last year entitled ”Basic Ideas in Mathematics,” and this year, following a suggestion of my wife, I changed the name to “The Beauty of Mathematics”. Another … Continue reading

Posted in Teaching | 26 Comments

A Proof by Induction with a Difficulty

  The time has come to prove that the number of edges in every finite tree is one less than the number of vertices (a tree is a connected graph with no cycle). The proof is by induction, but first you need … Continue reading

Posted in Teaching, What is Mathematics | Tagged , | 16 Comments