RpTheHotrod Posted May 12, 2012 Share Posted May 12, 2012 Does .99 repeating (.99 to an infinite number of 9s) equal 1? It does in fact equal 1. I'm just going to say that here. Now, as to why...I will give a very simple why and then a detailed why. SIMPLE WHY: First of all, I will give you a basic situation in which to determine how .99 repeating could equal one. Imagine that a baseball is being thrown from first base to second base. For the case of this situation let's pretend that it is being thrown in slow motion so we can carefully observe the ball. Now, in order for it to reach it's destination, the ball at some point will cross the halfway point in between the two bases. __________|__________ As the ball continues along its path, it crosses the halfway point in between the halfway point of the two bases and second base. However, it's speed remains constant. _______________|_____ As the ball continues further, it crosses yet another halfway point _________________|___ and again... ___________________|_ and so on. As the ball continues to travel, the speed remains the same, as the ball is crossing halfway points faster and faster and faster. Now, using simple logic, one could attempt to declare that the ball would NEVER reach its destination because there will ALWAYS be another half for the ball to have to cross.....even if the number is so minuscule and small that it could never be possibly measured by mankind. However, in the real word, the ball in fact reaches its destination, despite the outcry of simple logic. The halfway mark starts at .5, then moves onto .25, and so on. Eventually the halfway mark is such a large decimal number that at SOME point the number actually breaches and goes to 1. Otherwise, no object, or person, would ever reach any kind of destination. DETAILED WHY: The fact of the matter is, in some cases, an infinite series of numbers that go into infinity can actually have a sum result generated. That's right. In SOME cases, you can add ALL of infinity and get a true number result. For this example's sake, we are going to use a normalized rate, which is an unchanging number that is multiplied by the previous answer. For example, 1, 2, 4, 8, 16... this infinite series goes on forever, and as you can tell, the constant being multiplied by the previous is 2. 1 * 2 = 2. 2 * 2 = 4. 4 * 2 = 8. 8 * 2 = 16, and so on. Now, rates by no means have to be whole numbers. What happens if we start at 10 with a rate of .5? 10, 5, 2.5, 1.25, .625, .3125, and so on. Now, despite that these numbers will go into INFINITY...you'll constantly be dividing by half, you can actually get a REAL SUMMATION of ALL the infinity numbers. The formula for this is while -1 < rate < 1 (in our example rate = .5 which is between -1 and 1) then First number (in this example, 10) -------------- (divided by) 1 - rate [in this example, (1 - .5)] so our problem would be 10 divided by (1 - .5) Do we get an error? Do we get an infinite number that goes on forever? Actually, no. If we were to take our example of 10 (10), then adding 5 (15), then adding 2.5 (17.5), and so on to infinity, we would eventually have a total sum of 20. Crazy, eh? What does this prove? At some point, a decimal number going on into infinity and the difference between it and another number much like it becomes so immeasurable that there is no difference, at all and it equals each other. Despite there always being a halfway point the ball breaches, for the halfway point eventually is SO small that the halfway point ceases to exist and the ball reaches its destination. So yes, .9 may not = 1. .9999999 may not = 1. But eventually .99999999999999999... to infinity becomes so small it breaches the immeasurable point and it equals 1. If it didn't, then no object in time or space would be able to ever reach its destination. Link to comment Share on other sites More sharing options...
Alexrd Posted May 12, 2012 Share Posted May 12, 2012 That's a paradox. P.S: 0.999... Link to comment Share on other sites More sharing options...
Boba Rhett Posted May 12, 2012 Share Posted May 12, 2012 Yo dawg, I heard you liked rational numbers so we put all of the rational numbers contained within 1 inside of .999 repeating so you can have them contain the same set of rational numbers and therefor equal each other. Link to comment Share on other sites More sharing options...
Pho3nix Posted May 12, 2012 Share Posted May 12, 2012 I got dizzy Link to comment Share on other sites More sharing options...
Lady Jedi Posted May 20, 2012 Share Posted May 20, 2012 Yeah, I stopped reading after the baseball got where it was going. But seriously just round .9999999........ and it's totally 1. 0_o Link to comment Share on other sites More sharing options...
Boba Rhett Posted May 20, 2012 Share Posted May 20, 2012 Saw this and thought of this thread. Link to comment Share on other sites More sharing options...
mimartin Posted May 21, 2012 Share Posted May 21, 2012 I'd rather have a whole beer than .99999999... of a beer. Even if they are the same. Link to comment Share on other sites More sharing options...
Darth Avlectus Posted October 13, 2012 Share Posted October 13, 2012 By simply rounding up to the nearest whole number maybe? We're essentially talking about that theory that you could keep dividing by half and either add it ant never reach 1 or subtract it and never reach zero. There's a point at which the numbers are so infinitesimally small it isn't even negligible anymore to count, it just might as well be nothing in a practical sense relative to the scale you started. +1/2, +1/4, +1/8, +1/16, +1/32, +1/64... Percents of percents, I mean, we're splitting hairs here and doing all this math...for what? You could keep scaling down in theory but if every point up or down is half the distance of the last, from last, that it was to the prior, its insignificance to the original scale grows accordingly. Since it's practically nothing after a certain point you might as well say the addition/subtraction or just movement, has simply stopped. You could add another '9' to .99999999...... Most folks (and almost all calculators) would just simply round it out. Link to comment Share on other sites More sharing options...
90SK Posted October 19, 2012 Share Posted October 19, 2012 I was never one for mathematics. This concept is interesting, and seems accurate and sensible like most math, but I don't really see any practical applications apart from theoretical demonstrations. Link to comment Share on other sites More sharing options...
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