Puzzling Posted November 26, 2008 Share Posted November 26, 2008 Well, you treat the x like a constant. Check out the pic. Link to comment Share on other sites More sharing options...
iPsy Posted November 26, 2008 Share Posted November 26, 2008 Google is a new website where you ask it anything and you get the answer, have you heard of it? Link to comment Share on other sites More sharing options...
ricardo Posted November 26, 2008 Share Posted November 26, 2008 Starlight - you did a little mistake there. You got to multiply sqrt(x) with x before differentiating. http://img143.imageshack.us/img143/321/deriv2iz7.gif yeah but they are asking him to do it with logarythm, so according to logarythm properties it would be y=log3/2(x) no wait, it would be log y =log 3/2 (x) uh... oh shit I'm confused again Link to comment Share on other sites More sharing options...
Puzzling Posted November 26, 2008 Share Posted November 26, 2008 Yep, check out post #17. Link to comment Share on other sites More sharing options...
Starlight Posted November 26, 2008 Share Posted November 26, 2008 Well, you treat the x like a constant. Check out the pic. Hmmm I see. I guess I could try the product rule with it, but I'll have to see. I guess I'm not as advanced into it with logarithms, because I never did derivatives with logs. Like I said, I suck at math. :lol: Just thought I could help. And damn, Simon, there's nothing wrong with him asking here....:confused: Link to comment Share on other sites More sharing options...
iPsy Posted November 26, 2008 Share Posted November 26, 2008 Hmmm I see. I guess I could try the product rule with it, but I'll have to see. I guess I'm not as advanced into it with logarithms, because I never did derivatives with logs. Like I said, I suck at math. :lol: Just thought I could help. And damn, Simon, there's nothing wrong with him asking here....:confused: sorry, it was just a joke, please don't kill me....:bigcry: I'm rarely funny so I thought I might be able to crack a joke....obviously I was wrong :( :D, No worries ;) Link to comment Share on other sites More sharing options...
Starlight Posted November 26, 2008 Share Posted November 26, 2008 You worried me for a minute, Simon, I thought you were turning into another person...:P Link to comment Share on other sites More sharing options...
iPsy Posted November 26, 2008 Share Posted November 26, 2008 You worried me for a minute, Simon, I thought you were turning into another person...:P No worries ;) Link to comment Share on other sites More sharing options...
ricardo Posted November 26, 2008 Share Posted November 26, 2008 Yep, check out post #17. oh yes!! that's the correct answer! you're a genious! Link to comment Share on other sites More sharing options...
Starlight Posted November 26, 2008 Share Posted November 26, 2008 I think I see it too; I used the chain rule when it wasn't needed, I think. Link to comment Share on other sites More sharing options...
iPsy Posted November 26, 2008 Share Posted November 26, 2008 AHH!, I'm soo glad I don't need Maths for what I want to do ;) Link to comment Share on other sites More sharing options...
Puzzling Posted November 26, 2008 Share Posted November 26, 2008 Hehe, well, I must admit I needed a couple of minutes to remember how it was. But I think it's correct. Here it's done with the product rule: http://img152.imageshack.us/img152/8153/deriv3pi2.gif I bet there are ten more ways to do it :P. Link to comment Share on other sites More sharing options...
Ms Magpie Posted November 26, 2008 Share Posted November 26, 2008 Translation ruined my maths skillz. If I was asked this question last year, I'd be able to tell you the solution but now you already have it :D Link to comment Share on other sites More sharing options...
The Mad Hatter Posted November 27, 2008 Share Posted November 27, 2008 I'm still having trouble with Geometry:confused: isosceles what now? ISOSCELES TRIANGLE THEOREM IS MY FAVORITE THEOREM. <3 e.e Yeah, I love geometry, but I suck at it. I've got a B. :disappointed: Link to comment Share on other sites More sharing options...
Hotplay007 Posted November 27, 2008 Share Posted November 27, 2008 oh i know that stuff... until annie explained it. now i'm lost myself. Link to comment Share on other sites More sharing options...
zeoir Posted November 28, 2008 Share Posted November 28, 2008 ISOSCELES TRIANGLE THEOREM IS MY FAVORITE THEOREM. <3 e.e Yeah, I love geometry, but I suck at it. I've got a B. :disappointed: i like geometry too :blush: But i didn't do that well when i had that course a few years ago but aah well! Geometry is so damn simple! You've just gotta know a few things and you can do soo much with those few things :wideeyed: Link to comment Share on other sites More sharing options...
Lolly Pop Posted November 28, 2008 Share Posted November 28, 2008 Hi, well I'm not so sure about other countries but around here math is very much hated. That's not my case. The thing is that my teacher apllied us this exam with stuff we didn't even practice at all, he just mentioned the formulas and explained the tiniest example of each, now (after the exam) he's started with it and he just gave us an exercise and told me to do it in 2 ways, with the formula and with logarithm propertys, can you tell me how to do it with the second cause the way I did was wrong according to him. y= x√x I have a degree in math if that helps! I know that answer but need to work it out on paper! Link to comment Share on other sites More sharing options...
Lolly Pop Posted November 28, 2008 Share Posted November 28, 2008 *exhale* okay, here it goes: So you start out with the original problem. You want the derivative, right? 1. Another way to write the square root of x is x to the 1/2 power. This will make getting the derivative easier. 2. Since the x is now in parentheses when I put it in the 1/2 power, it is an indication of using the chain rule. You probably already know what that is, but you multiply the 1/2 with the first x, and subtract 1 from the exponent. So now it's 1/2x (x) to the -1/2 power. Along with that, you have to multiply the whole thing with the derivative of the x in the parentheses, which is 1, so nothing changes. 3. I rewrote it so that the answer would be a fraction...1/2x turns into x/2....and since anything with a negative exponent goes into the denominator....it turns back to the square root, but in the bottom. So the answer would be x/2 square root x.... ...I think. :lol: I hope that makes sense and I hope it's right. You'll have to tell me haha. Oh, and sometimes teachers don't like it when the radicals are in the denominator (I don't care, it's more work for me...:P) But at the bottom I simplified it more so that there's no radical at the bottom...but if that's not important then don't worry about it. Geez, I suck at math, haha. But I hope I was right! I got a totally different answer lol when there are 2 multiplying each other you have to use the principle f'g+g'f which means f=x g=x^1/2 so f'=1 g'=1/2x^-1/2 so when you apply the principle f'g+g'f you get (x^1/2)+(1/2x^-1/2)(x) = (3x^1/2)/2 I'll check again maybe I'm wrong! Link to comment Share on other sites More sharing options...
Lolly Pop Posted November 28, 2008 Share Posted November 28, 2008 maybe this is a bit more clearer instead of me trying to type it out haha Link to comment Share on other sites More sharing options...
indanomati Posted November 28, 2008 Share Posted November 28, 2008 ^Yep, that's how I learned to do it. Link to comment Share on other sites More sharing options...
nihcoldplay Posted November 28, 2008 Share Posted November 28, 2008 wow, that's confusing... :laugh3: Link to comment Share on other sites More sharing options...
Mig-El Posted November 29, 2008 Author Share Posted November 29, 2008 really sorry I was absent cause I had more difficult exams and I finally solved after several tries and discussion with a friend and aguing with my teacher too becasue of his unfair exam and I'm really sorry I made some of you push a little your brains and I pasted the ecuation wrongly. the second x with the radical is supposed to be the expontent (if that's right) so it's a little more difficult than what you thought but I noticed ricardo got it for the logarithms. I saw you did it ok but I wrote it the wrong way. I'll upload the correct one in a minute. Link to comment Share on other sites More sharing options...
Mig-El Posted November 29, 2008 Author Share Posted November 29, 2008 Here it is Link to comment Share on other sites More sharing options...
Ms Magpie Posted November 29, 2008 Share Posted November 29, 2008 Migel, this is totally irrelevant, but your handwriting is awesome. :o Link to comment Share on other sites More sharing options...
The Escapist Posted November 29, 2008 Share Posted November 29, 2008 We should make this the offical maths thread/ Link to comment Share on other sites More sharing options...
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