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How much is 4,596,411 pounds of sterling in U.S dollars.
It looks to me that if f(x) and g(x) are normal PDFs, then (f(x)+g(x))/2 is also a normal PDF. Is this so? What are the parameters of this new PDF? -- 대조 | Talk 09:22, 6 February 2007 (UTC)
What is the difference between kurtosis, as defined in our article, and Karl Pearson's measure of kurtosis, as defined by the R package 'moments'? I realise that the former subtracts 3 while the latter does not, but is that all, or are there other differences? -- NorwegianBlue talk 09:59, 6 February 2007 (UTC)
Haha -- AMorris (talk)● (contribs) 10:09, 6 February 2007 (UTC)
3 hours. Plus some time to figure out how they define half a hole. Since holes are usually cylindrical prisms, I would argue that half a hole would be shaped like a hemispherical prism. Depth would have to be standardized to some reference hole, so one would have to add some time to find a suitable reference hole. Manholes wouldn't be suitable because you'd need access to the sewrage system, unless one of the men was working for the city and was part of a hole-digging convention.
So what have we learned from all this? It's three hours and a bit, depending what the men work as when they're not digging holes and some thinking time. Hope that helps!
I found this question in a puzzle book. It says that there's no such thing as half a hole, since half a hole is a hole.
In school, we learnt about quadratic equations:
1. Their form: ax2 + bx + c = 0
2. The three methods of solving them (factorisation, completing the square and the quadratic formula)
3. How to use b2 - 4ac to find the nature of the roots of a quadratic equation.
I find quadratic equations fascinating. We're going to learn more about them next year, but I don't have next year's textbook yet. So, to help me prepare for next year, and my future, could you please tell me: 2x+4y=10,x+5y=11 1. Differentiation is to calculus as quadratic equations are to...what? Which fields of mathematics do quadratic equations play a major role in?
2. Some important applications of quadratic equations, especially in computing. —Preceding unsigned comment added by 218.186.9.3 ( talk • contribs)
Hello, and thanks for the replies, everyone. I'm taking my O Levels this year, so I'll be studying the A Level curriculum in the next 2 years. I understand that the quadratic formula is derived from the completing the square formula. We have not covered complex roots yet, so I'd appreciate any information on them. Thanks for telling me the formulas which usually become quadratic equations when linear functions are substituted into them. Since cubic equations and quadratic equations are somewhat similar, do cubic equations also have a discriminant and formula?
If and , what is the values of and ? I've figured out that it is and respectively, but I do not think that is correct...? Lol. Please help? This is kinda a homework question, yes... ► Adriaan90 ( Talk ♥ Contribs ) ♪♫ 13:29, 6 February 2007 (UTC)
Here's a longer explanation..(try the above first it probably is a better way to learn how to do this)
0.2x - 0.1y = 0,03
adding 0.1y to both sides, the equation becomes:
0.2x = 0.03 + 0.1y (multiply by five is the same as divide by 0.2 to give just x..) x = 0.15 + 0.5y
The second equation was
0.4x + 1.2y = 3 (replacing x by 0.15 + 0.5y ..) 0.4(0.15 + 0.5y) + 1.2y = 3 (expand the multiplication in the brackets) 0.6 + 0.2y + 1.2y = 3 0.6 + 1.4y = 3 1.4y = 2.4 14y = 24 y = 24/14 = 12/7 =1 5/7
You can do the same for y to get a value for x - unfortunately I can't find a simple explanation for this on wikipedia.
However you could look at http://www.themathpage.com/alg/simultaneous-equations.htm , this page is also quite clear http://www.mathcentre.ac.uk/resources/workbooks/mathcentre/web-simultaneous1.pdf (neads adobe acrobat). The equations you have are called "simultaneous linear equations". There 'simultaneous' because there are two or more variables in one equation. (linear because there are no powers like x squared or x cubed..). If you want to search for other answers - be warned a lot of the pages cover examples where there are many unknowns eg 4a+7b+1.3c+0.5d = 4 ... the method is the same but might seem confusing.
Try the links or look at the method above and see if it can make sense. If you didn't understand the steps I used above then ask. 87.102.13.26 14:46, 6 February 2007 (UTC)
4x+3y=15 divide by 4 gives x+0.75y = 15/4 or 0.2x + 7y = 1 divide by 0.2 gives x + 7/0.2y = 1/0.2 ie x+35y=5
and then rearrange to get the equation in terms of x eg x= 15/4 - 0.75y
then you can replace x in the other equation... (that's two steps - as you get better at it you might be able to do it in just one step) 87.102.13.26 18:19, 6 February 2007 (UTC)
43?
Or you can use a calculator. —Preceding unsigned comment added by Johnnyb2963 ( talk • contribs)
Easy question. By the definition of two independent events A and B, Pr(A ∩ B) = Pr(A)Pr(B). It can also be shown that A is independent of B′ (the complement event of B) and vice-versa. What I'd like to know is whether A′ and B′ are independent, given that A and B are independent. Thanks in advance. --
mattb @ 2007-02-06T19:31Z
@ 2007-02-06T20:16Z
Mathematics desk | ||
---|---|---|
< February 5 | << Jan | February | Mar >> | February 7 > |
Welcome to the Wikipedia Mathematics Reference Desk Archives |
---|
The page you are currently viewing is a transcluded archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages. |
How much is 4,596,411 pounds of sterling in U.S dollars.
It looks to me that if f(x) and g(x) are normal PDFs, then (f(x)+g(x))/2 is also a normal PDF. Is this so? What are the parameters of this new PDF? -- 대조 | Talk 09:22, 6 February 2007 (UTC)
What is the difference between kurtosis, as defined in our article, and Karl Pearson's measure of kurtosis, as defined by the R package 'moments'? I realise that the former subtracts 3 while the latter does not, but is that all, or are there other differences? -- NorwegianBlue talk 09:59, 6 February 2007 (UTC)
Haha -- AMorris (talk)● (contribs) 10:09, 6 February 2007 (UTC)
3 hours. Plus some time to figure out how they define half a hole. Since holes are usually cylindrical prisms, I would argue that half a hole would be shaped like a hemispherical prism. Depth would have to be standardized to some reference hole, so one would have to add some time to find a suitable reference hole. Manholes wouldn't be suitable because you'd need access to the sewrage system, unless one of the men was working for the city and was part of a hole-digging convention.
So what have we learned from all this? It's three hours and a bit, depending what the men work as when they're not digging holes and some thinking time. Hope that helps!
I found this question in a puzzle book. It says that there's no such thing as half a hole, since half a hole is a hole.
In school, we learnt about quadratic equations:
1. Their form: ax2 + bx + c = 0
2. The three methods of solving them (factorisation, completing the square and the quadratic formula)
3. How to use b2 - 4ac to find the nature of the roots of a quadratic equation.
I find quadratic equations fascinating. We're going to learn more about them next year, but I don't have next year's textbook yet. So, to help me prepare for next year, and my future, could you please tell me: 2x+4y=10,x+5y=11 1. Differentiation is to calculus as quadratic equations are to...what? Which fields of mathematics do quadratic equations play a major role in?
2. Some important applications of quadratic equations, especially in computing. —Preceding unsigned comment added by 218.186.9.3 ( talk • contribs)
Hello, and thanks for the replies, everyone. I'm taking my O Levels this year, so I'll be studying the A Level curriculum in the next 2 years. I understand that the quadratic formula is derived from the completing the square formula. We have not covered complex roots yet, so I'd appreciate any information on them. Thanks for telling me the formulas which usually become quadratic equations when linear functions are substituted into them. Since cubic equations and quadratic equations are somewhat similar, do cubic equations also have a discriminant and formula?
If and , what is the values of and ? I've figured out that it is and respectively, but I do not think that is correct...? Lol. Please help? This is kinda a homework question, yes... ► Adriaan90 ( Talk ♥ Contribs ) ♪♫ 13:29, 6 February 2007 (UTC)
Here's a longer explanation..(try the above first it probably is a better way to learn how to do this)
0.2x - 0.1y = 0,03
adding 0.1y to both sides, the equation becomes:
0.2x = 0.03 + 0.1y (multiply by five is the same as divide by 0.2 to give just x..) x = 0.15 + 0.5y
The second equation was
0.4x + 1.2y = 3 (replacing x by 0.15 + 0.5y ..) 0.4(0.15 + 0.5y) + 1.2y = 3 (expand the multiplication in the brackets) 0.6 + 0.2y + 1.2y = 3 0.6 + 1.4y = 3 1.4y = 2.4 14y = 24 y = 24/14 = 12/7 =1 5/7
You can do the same for y to get a value for x - unfortunately I can't find a simple explanation for this on wikipedia.
However you could look at http://www.themathpage.com/alg/simultaneous-equations.htm , this page is also quite clear http://www.mathcentre.ac.uk/resources/workbooks/mathcentre/web-simultaneous1.pdf (neads adobe acrobat). The equations you have are called "simultaneous linear equations". There 'simultaneous' because there are two or more variables in one equation. (linear because there are no powers like x squared or x cubed..). If you want to search for other answers - be warned a lot of the pages cover examples where there are many unknowns eg 4a+7b+1.3c+0.5d = 4 ... the method is the same but might seem confusing.
Try the links or look at the method above and see if it can make sense. If you didn't understand the steps I used above then ask. 87.102.13.26 14:46, 6 February 2007 (UTC)
4x+3y=15 divide by 4 gives x+0.75y = 15/4 or 0.2x + 7y = 1 divide by 0.2 gives x + 7/0.2y = 1/0.2 ie x+35y=5
and then rearrange to get the equation in terms of x eg x= 15/4 - 0.75y
then you can replace x in the other equation... (that's two steps - as you get better at it you might be able to do it in just one step) 87.102.13.26 18:19, 6 February 2007 (UTC)
43?
Or you can use a calculator. —Preceding unsigned comment added by Johnnyb2963 ( talk • contribs)
Easy question. By the definition of two independent events A and B, Pr(A ∩ B) = Pr(A)Pr(B). It can also be shown that A is independent of B′ (the complement event of B) and vice-versa. What I'd like to know is whether A′ and B′ are independent, given that A and B are independent. Thanks in advance. --
mattb @ 2007-02-06T19:31Z
@ 2007-02-06T20:16Z