Number Theory/pi

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Question
Hello Vijilant,
1.Why pi is an irrational number, since pi=circumference/diameter(If  both circumference and diameter are integers, then pi will become rational? isn't it? But, I studied, pi cannot be written as ratios. What's going on here? Please explain me.

Answer
Hello Shameem
Every proof that PI is irrational is difficult and demands at least a very good understanding of analysis.  See for instance http://en.wikipedia.org/wiki/Proof_that_%CF%80_is_irrational

Of course both the circumference and diameter of a circle cannot be integers.  This is just another way of saying PI is irrational.

Best wishes

vijilant

Number Theory

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Vijilant

Expertise

Most questions on number theory, divisibility, primes, Euclidean algorithm, Fermat`s theorem, Wilson`s theorem, factorisation, euclidean algorithm, diophantine equations, Chinese remainder theorem, group theory, congruences, continued fractions.

Experience

Teacher of math for 50 years

Organizations
ATL

Publications
Journal of mathematics and its applications

Education/Credentials
BSc Hons Liverpool

Awards and Honors
State Scholarship 1955

Past/Present Clients
I taught John Birt, former Director of the BBC in 1961. His homework book was the most perfect I have ever marked. And also the most neat. I could tell he was destined for great things. One of my classmates was the poet Roger McGough, and I have a mention in his autobiography.

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