steveorino 7 #1 July 13, 2009 My son showed me this. What is up with this equation? steveOrino Quote Share this post Link to post Share on other sites
billvon 2,991 #2 July 13, 2009 It says that 3.99999999999999999. . . . is basically equal to four. It's not 100% correct; the bar over the 9 is an approximation and does not represent a real representable integer, so the equals sign is really an "approximately equals" sign. Quote Share this post Link to post Share on other sites
AggieDave 6 #3 July 13, 2009 Which is similar to the math used by NASA for some of the Mars missions... --"When I die, may I be surrounded by scattered chrome and burning gasoline." Quote Share this post Link to post Share on other sites
likearock 2 #4 July 13, 2009 And I thought that Speaker's Corner was supposed to be about Guns, Gays, or God. Anyway 3.9999... as an infinite series converges on the value 4, which makes it equivalent to 4 in certain respects. I'm sure some of the more mathematically inclined here can explain better. Quote Share this post Link to post Share on other sites
steveorino 7 #5 July 13, 2009 QuoteAnyway 3.9999... as an infinite series converges on the value 4, which makes it equivalent to 4 in certain respects Not sure how 3.999999999 ... = 4. Does 4.1111111 ... equal 4 too? steveOrino Quote Share this post Link to post Share on other sites
jerryzflies 0 #6 July 13, 2009 QuoteMy son showed me this. What is up with this equation? Nothing's wrong with it.If you can't fix it with a hammer, the problem's electrical. Quote Share this post Link to post Share on other sites
steveorino 7 #7 July 13, 2009 so 3.999999 .... = 4? steveOrino Quote Share this post Link to post Share on other sites
jerryzflies 0 #8 July 13, 2009 QuoteQuoteAnyway 3.9999... as an infinite series converges on the value 4, which makes it equivalent to 4 in certain respects Not sure how 3.999999999 ... = 4. Does 4.1111111 ... equal 4 too? No. 4.0 - 3.999... = 0.000........000....000...... but 4.111.... - 4.0 = 0.11111... Not very good at math, are you?If you can't fix it with a hammer, the problem's electrical. Quote Share this post Link to post Share on other sites
steveorino 7 #9 July 13, 2009 As a family therapist math was not a necessary strong suit. Still can't wrap around the explanation people are giving. I guess math is not a B&W concept like I thought. steveOrino Quote Share this post Link to post Share on other sites
turtlespeed 220 #10 July 13, 2009 Quote As a family therapist math was not a necessary strong suit. Still can't wrap around the explanation people are giving. I guess math is not a B&W concept like I thought. Never had to theraputise the Octomom did you?I'm not usually into the whole 3-way thing, but you got me a little excited with that. - Skymama BTR #1 / OTB^5 Official #2 / Hellfish #408 / VSCR #108/Tortuga/Orfun Quote Share this post Link to post Share on other sites
justinb138 0 #11 July 13, 2009 The problem is that multiplying 3.9... by 10 doesn't give you 39.9... It gives you 39.9...0. One number would end in 9, the other would end in a 0. Quote Share this post Link to post Share on other sites
steveorino 7 #12 July 13, 2009 makes sense ... thanks! steveOrino Quote Share this post Link to post Share on other sites
chasteh 0 #13 July 13, 2009 It depends on what kind of math you are talking about. Deductive math is very different from inductive math. The same is true of inductive reasoning versus deductive reasoning. Math (hopefully) is actually an extremely important factor in your field. When you speak, you are actually working through a math problem. When you are asking family members to explain their positions, you are working through a math problem as you find the contradictions between their statements. When you are a judge or an attorney in a court room, you are working through a complex math problem. It just looks different from the kind of "math" that most people are used to, the kind that uses numbers, matrixes, and a radix to define the Universe of Discourse in which those things reside. Quote Share this post Link to post Share on other sites
ryoder 1,590 #14 July 13, 2009 Quote It says that 3.99999999999999999. . . . is basically equal to four. It's not 100% correct; the bar over the 9 is an approximation and does not represent a real representable integer, so the equals sign is really an "approximately equals" sign. I just ran that equation on my 60MHz Intel Pentium, and it is indeed equal."There are only three things of value: younger women, faster airplanes, and bigger crocodiles" - Arthur Jones. Quote Share this post Link to post Share on other sites
steveorino 7 #15 July 13, 2009 Quote It depends on what kind of math you are talking about. Deductive math is very different from inductive math. The same is true of inductive reasoning versus deductive reasoning. Math (hopefully) is actually an extremely important factor in your field. When you speak, you are actually working through a math problem. When you are asking family members to explain their positions, you are working through a math problem as you find the contradictions between their statements. When you are a judge or an attorney in a court room, you are working through a complex math problem. It just looks different from the kind of "math" that most people are used to, the kind that uses numbers, matrixes, and a radix to define the Universe of Discourse in which those things reside. You get all that when I ask, "How does that make you feel?" ?? steveOrino Quote Share this post Link to post Share on other sites
jerryzflies 0 #16 July 13, 2009 Quotemakes sense ... thanks! No, it doesn't, because there are an INFINITE number of "9"s in both cases, since infinity+1 = infinity See www.newton.dep.anl.gov/newton/askasci/1995/math/MATH070.HTMIf you can't fix it with a hammer, the problem's electrical. Quote Share this post Link to post Share on other sites
chasteh 0 #17 July 13, 2009 It is precisely what occurs. Quote Share this post Link to post Share on other sites
beowulf 1 #18 July 13, 2009 looks fine to me. you have two equations. One was solved as x = 39.9 and the other was solved as x = 4 first equation is 10x = 39.99 with the 9 going on forver. x was solved as equaling 3.99 where 9 goes on forever. second equation is 10x-x = 39.9 - 3.9 both the 9s go on forever. x was solved as equaling 4. Very basic algebra. Math isn't for everyone. Quote Share this post Link to post Share on other sites
steveorino 7 #19 July 13, 2009 so in other words 3.999 ... = 4, right? steveOrino Quote Share this post Link to post Share on other sites
beowulf 1 #20 July 13, 2009 NO Your son was being sloppy and not showing that he was solving two different equations. The first boxed text should go under the 10x = 39.9 as the answer to that equation. The second equation is 10x - x = 39.9 - 3.9 answer is x = 4 Two equations two different answers. 4 does not equal 3.99. Quote Share this post Link to post Share on other sites
jerryzflies 0 #21 July 13, 2009 Quoteso in other words 3.999 ... = 4, right? 1/9 = 0.111111... 8/9 = 0.8888888... 1/9 + 8/9 = 1 0.11111.... + 0.88888.... = ?If you can't fix it with a hammer, the problem's electrical. Quote Share this post Link to post Share on other sites
likearock 2 #22 July 13, 2009 QuoteQuoteAnyway 3.9999... as an infinite series converges on the value 4, which makes it equivalent to 4 in certain respects Not sure how 3.999999999 ... = 4. Does 4.1111111 ... equal 4 too? No, but it does "equal" 4 1/9 in the same way that 3.999 ... equals 4. Quote Share this post Link to post Share on other sites
steveorino 7 #23 July 13, 2009 Quote And I thought that Speaker's Corner was supposed to be about Guns, Gays, or God.] math is sounding more and more like a religion to me. The answer depends on who you ask and many say it is semantic game, while others insist they are right and the others are wrong. Forgot to add .. some will insult you when you don't understand their version. steveOrino Quote Share this post Link to post Share on other sites
beowulf 1 #24 July 13, 2009 Do you understand what I was saying? Depending on the teacher, they might not accept that sloppyness. He should have told you he was solving two different equations not one. He was using the boxes to show two different answers to two different equations. There is no ambiguity in math. Quote Share this post Link to post Share on other sites
steveorino 7 #25 July 13, 2009 so that same "double" equation can't be written as one equation? steveOrino Quote Share this post Link to post Share on other sites
