{{
`${userDetail.user.displayName}${userDetail.user.cachedBungieGlobalDisplayNameCode ? `#${standardizeBungieGlobalCode(userDetail.user.cachedBungieGlobalDisplayNameCode)}` : ""}`}}
{{getUserClans()}}
7/29/2010 6:11:32 AM
50
Is y = sqrt(x) a function?
Well is y=sqrt(x) a function?
[Edited on 07.28.2010 10:12 PM PDT]
-
I am 100% certain that it is a function.
-
yes source: I am a math genius
-
[quote][b]Posted by:[/b] darkknight54 My calculator says it is.[/quote] And those are always right.....
-
My calculator says it is. [Edited on 07.29.2010 5:21 PM PDT]
-
Generally people ignore the negative value unless it's y=-sqrt(x)
-
It is since when you 'write' only sqrt you refer to the principle square root or positive one and to refer to the negative one you have to use -sqrt. Acorrding to this [url=http://mathworld.wolfram.com/SquareRoot.html]site[/url] "In common usage, unless otherwise specified, "the" square root is generally taken to mean the principal square root. The principal square root function sqrt(x) is the inverse function of f(x)=x^2 for x>=0." [Edited on 07.29.2010 8:32 AM PDT]
-
[quote][b]Posted by:[/b] darkknight54 [quote][b]Posted by:[/b] Mike_Bson [quote][b]Posted by:[/b] quickdog93 This is because a square root of a negative does not exist.[/quote]I don't expect everyone to be as good at math as I am, but damn. This is just ridiculous. Have you gone into Algebra II?[/quote] Yup. Just because something isn't [i]real[/i] doesn't mean it doesn't exist. lol. Are I funny?[/quote] lol
-
[quote][b]Posted by:[/b] SeraphvsIvdicii Your argument is irrelevant; the programmed calculation and display behaviours for a computing device do not correlate to the strict mathematical reality, especially on a device that supports only a single numerical output per input. The square root, taken as a MATHEMATICAL OPERATION, not as a routine in a computer of some sort, cannot qualify as part of a function without performing further operations on the result. See my previous post in this thread. [/quote]I see nothing wrong with what you say, and I now agree with you.
-
Obviously? I don't get this. Why wouldn't it be? Anyway, my turn, just for fun. (integral of)sqrt(arctanx) (dx) Have fun [Edited on 07.29.2010 12:25 AM PDT]
-
[quote][b]Posted by:[/b] SeraphvsIvdicii [quote][b]Posted by:[/b] Mike_Bson [quote][b]Posted by:[/b] SeraphvsIvdicii No, it is not. You people really need the stop with the self-delusion and wanton misinformation of others.[/quote]What is this I don't even. In all seriousness, when you put ''sqrt'' as a function, it assumes you means the principle square root. Seriously, do this on ANY graphing utility. EDIT- Saw what you quoted, and I do not quite know what you mean; elaborate, please. [/quote] Your argument is irrelevant; the programmed calculation and display behaviours for a computing device do not correlate to the strict mathematical reality, especially on a device that supports only a single numerical output per input. The square root, taken as a MATHEMATICAL OPERATION, not as a routine in a computer of some sort, cannot qualify as part of a function without performing further operations on the result. See my previous post in this thread.[/quote] This makes sense to me.
-
[quote][b]Posted by:[/b] Mike_Bson [quote][b]Posted by:[/b] SeraphvsIvdicii No, it is not. You people really need the stop with the self-delusion and wanton misinformation of others.[/quote]What is this I don't even. In all seriousness, when you put ''sqrt'' as a function, it assumes you means the principle square root. Seriously, do this on ANY graphing utility. EDIT- Saw what you quoted, and I do not quite know what you mean; elaborate, please. [/quote] Your argument is irrelevant; the programmed calculation and display behaviours for a computing device do not correlate to the strict mathematical reality, especially on a device that supports only a single numerical output per input. The square root, taken as a MATHEMATICAL OPERATION, not as a routine in a computer of some sort, cannot qualify as part of a function without performing further operations on the result. See my previous post in this thread. [Edited on 07.29.2010 12:05 AM PDT]
-
[quote][b]Posted by:[/b] SeraphvsIvdicii No, it is not. You people really need the stop with the self-delusion and wanton misinformation of others.[/quote]What is this I don't even. In all seriousness, when you put ''sqrt'' as a function, it assumes you means the principle square root. Seriously, do this on ANY graphing utility. It only assumes +/- is you write such. That's the point of the +/- symbol. [Edited on 07.29.2010 12:01 AM PDT]
-
[quote]Original Post By: RGJ798 Within the set of all real numbers this is a function.[/quote] No, it is not. You people really need the stop with the self-delusion and wanton misinformation of others. [Edited on 07.28.2010 11:55 PM PDT]
-
Within the set of all real numbers this is a function.
-
Well, x can only equal one value of f(x)=y, so if x=4, y= +/-2. That is more than one answer. So, no.
-
[quote][b]Posted by:[/b] darkknight54 Yup. Just because something isn't [i]real[/i] doesn't mean it doesn't exist. lol. Are I funny?[/quote]This is why I do not like the name ''imaginary numbers''. All numbers are just as real, they are all made up by man to identify and solve problems. ''Real'' and ''imaginary'' are just names made up to identify them for simplicity. Saying 1 is more ''real'' than i because 1 seems more concrete is like saying that ''apple'' is a more ''real word'' than ''humility,'' because the thing that humility represents is not concrete and is only made up by man. All words and numbers are just made by people to represent stuff.
-
[quote][b]Posted by:[/b] Mabian [quote][b]Posted by:[/b] Gman5434 [quote][b]Posted by:[/b] MadMax888 Yes, because for each value of y there is only 1 value of x.[/quote] I thought that sqrt meant that you take plus or minus then sqrt. So then it wouldn't be a function?[/quote] Square root means you take the root of the number that is x, and [i]then[/i] turn it into a plus or minus, because both the positive and negative numbers are correct answers. You will find that often people take only the positive value. I can't exactly remember the whole explanation for it...[/quote] Explanation for why it's positive and negative: If I square root 4, then I get +2 and -2 because I can multiply +2*+2 and get 4, or -2*-2 and get 4, so both of them are solutions to the square root. And although it's been a while since Algebra, I believe that it is a function. And wow, never thought I'd see the day where I remember more geometry than I do algebra. I'm thinking of graphing parabolas for some reason =/
-
[quote][b]Posted by:[/b] Mabian [quote][b]Posted by:[/b] milla da killa And also the +/- is where imaginary gets used, regardless you wouldn't plot the values because it's still undefined. While the numbers can be used for solving an equation, they don't get used for graphing since they don't actually exist.[/quote] Not quite what I meant. I didn't mean that you would have the +/- [i]inside[/i] the square root, because that leads to all sorts of complications. I was meaning [i]outside[/i] the square root, which basically means that once you've solved the root, the answer is the positive or negative form of the answer you got, which is true, since either 4 or -4 squared will get you your original X. Negative numbers are okay with square roots as long as the negative is outside the square root. Unless you're dealing with imaginary numbers. Which are what drove people to discover alcohol.[/quote] Yeah, that's what I meant/was saying.
-
[quote][b]Posted by:[/b] Mabian [quote][b]Posted by:[/b] Gman5434 [quote][b]Posted by:[/b] MadMax888 Yes, because for each value of y there is only 1 value of x.[/quote] I thought that sqrt meant that you take plus or minus then sqrt. So then it wouldn't be a function?[/quote] Square root means you take the root of the number that is x, and [i]then[/i] turn it into a plus or minus, because both the positive and negative numbers are correct answers. You will find that often people take only the positive value. I can't exactly remember the whole explanation for it...[/quote] It's not simply a matter or "picking" a positive or negative result. A [i]function[/i] is a strictly defined mathematical construct for which there is only one output per input. The square root operation returns two results for any complex argument. As such, the relation between a variable and the unmodified square root of another variable is not a function. The relation in question can be made a function by taking the absolute value, or the opposite of the absolute value, of the right side. [Edited on 07.28.2010 11:03 PM PDT]
-
[quote][b]Posted by:[/b] darkknight54 [quote][b]Posted by:[/b] Mike_Bson [quote][b]Posted by:[/b] quickdog93 This is because a square root of a negative does not exist.[/quote]I don't expect everyone to be as good at math as I am, but damn. This is just ridiculous. Have you gone into Algebra II?[/quote] Yup. Just because something isn't [i]real[/i] doesn't mean it doesn't exist. lol. Are I funny?[/quote] I meant it's not a real number. It's an imaginary number.
-
[quote][b]Posted by:[/b] Mike_Bson [quote][b]Posted by:[/b] quickdog93 This is because a square root of a negative does not exist.[/quote]I don't expect everyone to be as good at math as I am, but damn. This is just ridiculous. Have you gone into Algebra II?[/quote] Yup. Just because something isn't [i]real[/i] doesn't mean it doesn't exist. lol. Are I funny?
-
[quote][b]Posted by:[/b] Jdom765 I say no. Since y=x^2 fails the horizontal line test and since y=sqrt(x) is the inverse of that. Therefore it can't be a function.[/quote]
-
[quote][b]Posted by:[/b] Mike_Bson [quote][b]Posted by:[/b] quickdog93 This is because a square root of a negative does not exist.[/quote]I don't expect everyone to be as good at math as I am, but damn. This is just ridiculous. Have you gone into Algebra II?[/quote] cool dude.
-
[quote][b]Posted by:[/b] Mike_Bson Well, when you just have sqrt(x) that is usually seen as the principle square root, i.e. the positive one. If you type in y=+/-x, then that is the same as graphing two functions;y=x, y=-x. This means y does not have one distinct real solution, ergo is not a function. [/quote] Well that's disappointing. I thought there would be more to it then well you just [i]assume[/i] that you're referring to the positive graph. Regardless thanks to all for their contributions.
-
[quote][b]Posted by:[/b] Gman5434 [quote][b]Posted by:[/b] MadMax888 Yes, because for each value of y there is only 1 value of x.[/quote] I thought that sqrt meant that you take plus or minus then sqrt. So then it wouldn't be a function? Ex: if x was 4. Then y would be +2 and -2 right?[/quote]I believe that would be true if it was x=y^2, but not y=sqrt(x) though that's some calc stuff for ya. it really only matters when finding the area of something revolved around the y axis iirc [Edited on 07.28.2010 10:58 PM PDT]
-
[quote][b]Posted by:[/b] Gman5434 [quote][b]Posted by:[/b] milla da killa Yeah, my bad, got them mixed up. Been a while since I took math. And also the +/- is where imaginary gets used, regardless you wouldn't plot the values because it's still undefined. While the numbers can be used for solving an equation, they don't get used for graphing since they don't actually exist.[/quote] You can graph complex numbers on an imaginary plane just not a real one.[/quote]Well, if you do the thing that WolfRam does, then that makes sense. It shows the real part, and the imaginary part.
