How much is one divided by zero? Don’t ask…

The chairman of the press council of India, Justice Markandey Katju, wrote an article in The Hindu on September 3 on education.

Titled ‘Professor, heal thyself’, it contained this paragraph:

The level of intellect of many teachers is low, because many of them have not been appointed on merit but on extraneous considerations. To give an example, when I was a judge of Allahabad High Court I had a case relating to a service matter of a mathematics lecturer in a university in Uttar Pradesh.

Since the teacher was present in court I asked him how much one divided by zero is equal to.

He replied, “Infinity.”

I told him that his answer was incorrect, and it was evident that he was not even fit to be a teacher in an intermediate college. I wondered how had he become a university lecturer (In mathematics it is impermissible to divide by zero. Hence anything divided by zero is known as an indeterminate number, not infinity).

Not surprisingly, two wise readers of The Hindu have corrected the press council chief through letters to the editor:

In his article “Professor, teach thyself” (Sept. 3), chairman of the Press Council of India, Markandey Katju, has cited an incident that took place when he was a judge of the Allahabad High Court. He says he chided a mathematics lecturer, whose case he was hearing, and told him that he was not fit to be even a teacher because he (the lecturer) said one divided by zero was infinity.

Justice Katju claims that anything divided by zero is indeterminate. He is wrong and the lecturer was right because any non-zero number divided by zero is infinity. It is zero divided by zero that is indeterminate.

While I can understand the plight of the poor lecturer who did not have the courage to correct the judge hearing his case, I am appalled at the timidity of “some of the top senior academicians” of Jawaharlal Nehru University, to whom Justice Katju narrated the incident. I wonder why they let his fallacy pass unchallenged. Justice Katju must seek out the mathematics lecturer and apologise to him.

Kanan Vihari Jaswal, Noida

I would like to digress from the primary point made in the article — with which I completely agree — and talk about the mathematics lecturer’s answer. “Infinity” is indeed the correct answer to the question posed by Justice Katju to the lecturer. 0/0 is indeterminate because it can take multiple values depending on the limit being calculated (for example 2x/x; x->0 is 2 , 5x/x; x->0 is 5) whereas any finite number divided by 0 (eg 1/0) is an impermissible operation, which is just another way of saying that the result is infinite (an absurdly large number).

Siddharth Tiwari, Kanpur


Also read: ‘I have a poor opinion of most media people’

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