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Use the estimate in the text based on the Prime Number Theorem to give approximate values of the following. (a) The number of primes between 1 and 1030. (b) The number of primes between 1 and 1029.

User Jqgsninimo
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1 Answer

3 votes

Answer:

a)148.47

b)148.34

Explanation:

Let π(x) be the prime-counting function that gives the number of primes less than or equal to x, for any real number x. For example, π(7) = 4 because there are four prime numbers (2, 3, 5, 7) less than or equal to 7.

We can see that π(7)=π(10) because there are four prime numbers (2,3,5,7) less than or equal to 10.

A good aproximation for π(x) is x / log x, where log x is the natural logarithm of x.

a)The number of primes between 1 and 1030.

1030/log(1030)=148.47

b) The number of primes between 1 and 1029.

1029/log(1029)=148.34

Extra: π(1029)=π(1030) because 1030 is not a prime.

User Bronx
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