Archive for February 2010
So you think you know how to multiply decimals?
Posted by: Gary Ernest Davis on: February 12, 2010
Finite and infinite decimals In school students are taught how to add , subtract, and multiply, – but usually not divide – decimal numbers. There is a big catch however. The decimal numbers are not infinite decimals, such as we would obtain from or The decimal numbers dealt with in school are all finite decimal […]
How do I prove that 5 divides x^5 – x? The joys of modular arithmetic
Posted by: Gary Ernest Davis on: February 11, 2010
On Physics Forums , ninjagod123 asked: “How do I prove that 5 divides ??” In this question, the variable “” should be thought of as restricted to integer values – in fact positive integer values – since divisibility for fractions or real numbers in general is trivial. So another way to ask the question is: […]
