what is the greatest prime you must consider to test whether 4384 is prime?

Question

jim_thompson5910 · Answer

Take the square root of the given number and locate the closest prime number that is smaller than the result


sqrt(4384) = 66.21178


The smallest prime number that is smaller than 66.21178 is 61


So 61 is the greatest prime you need to test to see whether 4384 is prime

jim_thompson5910 · Answer

You'll notice that 4384 is even, so 2 is a factor. This means that 4384 is not prime. This means we don't have to test all the way up to 61 and we can stop at 2.

anonymous · Answer

thank you for explaining just wasn't getting the example in the book

jim_thompson5910 · Answer

you're welcome