# Category Teaching

## Yet another proof that primes are infinite

In CS131, we see the “Proof from the Book” due to Euclide that the number of prime numbers is infinite. Here is another favorite proof that is based on elementary facts. Suppose that is a list of all the primes. From what we have learnt about the sum of geometric progressions we know that for […]

## Denoising binary images

Data science is transforming the world: we already see self-driving cars moving from research to production, data-driven cancer diagnostic systems, machine learning trader bots and lots of other exciting technologies because the corresponding problems have been reduced to understanding data. While the science of data for centuries was known as statistics, computer scientists, together with […]

## Riddles from the White House

It is well known that President Obama was a strong supporter of computer science, and was the first US President to write code. During his presidency, brain teasers were published from the White House web page. I came across this nice riddle that illustrates how Boolean logic can be used to achieve success in cooperation. […]