Irrational and Prime NumbersDate: 4/1/96 at 7:14:46 From: Leigh Ausband Subject: Pi A question from Mrs. Fields' seventh grade math classes at Robert Smalls Middle School, Beaufort, SC. Please explain the concept of irrational numbers. Also, do you think there is a highest prime number? Sincerely, Tiffanne' Mahomes Hi Tiffanne' Mathematicians have proven that prime numbers are infinite - so no, there isn't a highest prime number. However, there IS a 'largest known prime' - the highest one we've found to date. According to the sci.math FAQ, this is (2 to the 859433rd power) -1. Wow, that's big! Irrational numbers are numbers that can't be expressed as a ratio between two integers. Some rational numbers: 1/3, 8, -295, -983 An example of an irrational number is the square root of 2. As far as I know, the square root of two was the first known irrational number. Do you know the Pythagorean theorem? At http://mathforum.org/pow/solution15.html there's a great picture of this theorem, which says that in a right triangle, the square on the first short leg added to the square on the second short leg equals the square on the hypotenuse. Well, what happens if you have a right triangle with short sides of 1 and 1? The hypotenuse winds up having a length of the square root of two! -Doctor Jodi, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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