Domain Definition and 704 Threads

  1. L

    How do you set up an integral integrating two functions within a domain?

    How do you set up an integral integrating two functions within a domain?? Homework Statement I have to integrate (2 + x + y) within the domain that is the area between 0 and 1 and (x+y<=1) I know how to integrate well, I think it's a double integral but I'm not really sure what the range...
  2. O

    Domain and range of this function?

    Homework Statement (1/(x+7))-5 find the domain and range. im having trouble graphing this one on my calculator, because when i zoom out the graph looks a lot different than when i zoom in. i think i have an answer though, so i need a quick check. domain: none (infinite) rangE: 0 to -10?
  3. A

    Chemistry Electron Domain Geometry vs Molecular Shape

    What's the difference between "Electron Domain Geometry" and "Molecular Shape"? Please help! Thanks
  4. A

    Domain of g(x) = (x-2)/(x^2-9) |x|≠3

    for g(x) = (x-2) / (x^2 -9) the domain of the function would be simply to have the denominator not equal to 0, which in this case would be x = 3. but.. the solution states that it is -3 and 3 cannot be used. this is confusing seeing that -3^2 -9 = -18 which is not 0. maybe it...
  5. N

    Numerical PDE's II - Circular Domain

    Homework Statement Approximate the solution of: \frac{\partial^{2}u }{{\partial r^{2} }} + \frac{1}{r}\frac{\partial u}{\partial r} + \frac{1}{r^{2}}\frac{\partial^{2}u}{\partial \theta^{2}} = 0, 1<r<3, 0<\theta<\pi, u(1,\theta) = 1-\cos(\theta),u(2,\theta)=u(r,0)=0 u(r,\pi)=4-2r...
  6. C

    Domain of y=sqrt(cosx): 1st & 4th Quadrant of Unit Circle

    What would the domain of y = sqrt(cosx) be in mathematical terms. I know that it is all the reals that lie in the first and fourth quadrant of the unit circle, but how would you express that in mathematical terms?
  7. R

    Are the following functions? Give domain and range

    Homework Statement State if the following is a function. If yes, write domain and range. A. {(x,y): y=(x^1/2) ; x,y are real numbers and x>0} B. {(x,y): y^2=x ; x is real numbers and x>0} Homework Equations A relation is called function if each element of the domain...
  8. A

    Domain of a Differential Equation

    Find the particular solution y=f(x) to dy/dx=(1+y)/x given that f(-1)=1 and state its domain. My answer was: 2|x|-1, x ∈ ℝ/{0} Apparently, the domain should be x<0 Solving the differential equation was not an issue at all, but I have no idea why the domain is restricted to x<0. I...
  9. D

    Domain & Range Homework: Difference Explained

    Homework Statement I don't really know how to ask this, so I'll get straight into an example. x:x\in(-\infty,\infty) but x\neq1 x:x\in(-\infty,1)\cup(1,\infty) what is the difference between these two intervals? Homework Equations The Attempt at a Solution
  10. quasar987

    Is 0 Considered a Prime Element in an Integral Domain?

    [SOLVED] Is 0 a prime? Am I missing something or is 0 a prime element in an integral domain? In the definition of prime element p of an integral domain, we only ask that the ideal generated by p, be prime. Well (0) is obviously prime because if ab=0 in an integral domain, then it is that...
  11. T

    Is P(X<Y) Equal to 1/3 for f(x,y) = e^{-x-2y}?

    If f(x,y) = e^{-x-2y} find P(X<Y) . So is this equaled to 1 - P(X>Y) = 1 - \int\limits_{0}^{\infty} \int\limits_{0}^{x} e^{-x-2y} \ dy \ dx = \frac{1}{3}?
  12. I

    Understanding Domain Notation: Explaining 2<x<4 in Graphs and Equations

    Homework Statement I have to do a few graphs and some equations with certain domains but I've never seen the domain written in this way: Usually I see the domain written with something like 2<x<4. What exactly does the above mean?
  13. 1

    Domain & Range: Calculus Help, Graphs

    Calculus Help, Please. (Domain, Range, Graphs) Homework Statement Determine its domain and range. f(x) = {2x+1, x<0 {2x+2, x => 0 f(x) = {x^2 + 2, x<=1 {2x^2 + 2, x >1 f(x) = { |x| + 1, x<1 { -x +1, x=>1 Homework Equations No equations...
  14. N

    What Is an Alternative Domain for Sec(x)?

    Homework Statement A problem in my textbook gives the domain of sec x as [0,(pi/2)) U ((pi/2), pi]. This makes perfect sense of course. However, it is asking for an alternate domain. I've looked at the graphs of both sec x and arcsec x to try to figure out a different domain for sec x(I looked...
  15. G

    Domain of f(x) = (2x^2 + 25)^(0.5) + 1 - Help Needed

    I was wondering if there's any symbol i could use for the domain of this question f(x) = (2x^2 + 25)^(0.5) + 1 as we can see that , f(x) will always be greater or equal to zero , was wondering what would the domain be ? Could anyone help me out ? thanks
  16. M

    What bracket is used to denote a number is excluded from a domain?

    When asked to find the domain, what bracket is used to denote that a number is excluded or included in the domain, ( or [?
  17. S

    Finding the domain of the square root of a polynomial

    I was just going through some problems in a maths journal for undergraduate level i found a sum seeming simple but i am not able to solve it completely find domain of \sqrt{x^{12} - x^9 + x^4 -x +1}i know domain includes all negative value , all positive value >1 , but i can't get anything...
  18. rocomath

    Domain, why are they both not defined?

    I'm currently self-studying ODE, text by Morris Tenenbaum, and I am confused by these 2 problems. z=\sqrt{-(x^2 + y^2)} D: (0,0) z=\sqrt{-(x^2 + y^2 +1)} undefined
  19. G

    What is the range of g(x) for arctan(2x)?

    http://www.math.yorku.ca/Who/Faculty/Kochman/M1300/solutions/solF04/SFE.pdf Question 2. I agree that the range of arctan is [-pi/2, pi/2], however due to the fact that we have arctan(2x), not just arctan(x), wouldn't that mean that the range of the g(x) function would be [-pi/4, pi/4]...
  20. B

    Finding the Domain of a Vector Function

    Homework Statement how to find the domain of an vector function? Homework Equations The Attempt at a Solution
  21. H

    Solving for Domain and Asymptotes in Functions f(x) and g(x)

    Please Help with Domain... Homework Statement For f(x) Determine Domain, Vertical Asymptote and x and y intercepts. then State and graph the effect of the modifications and sketch the graph of f(x) Given f(x) = - log3(x – 1) + 2 For g(x) determine domain, Horizontal asymptote and x...
  22. P

    Trying to determine domain of f(t)=4.5e^t

    heres a question I am trying to figure out if this equations domain f(t)=4.5e^t where e is 2.1783 im thinking that the answer is all positve numbers. because it can't equal zero so all negative numbers cause it to be 0
  23. R

    Why is the Domain of y=2x^2+12x+12 the Set of Real Numbers?

    Can someone please tell me why the domain of y=2x^2+12x+12 is x elementof IR
  24. H

    Domain and range, functions of 2 variables

    I'm having a bit of trouble grasping the domain and range of functions of 2 variables. Does anyone know of any helpful tutorials that will help me get the hang of this concept? Any help appreciated.
  25. M

    Find the natural domain of the function

    i have this question that i don't totally get what it wants exactly so if anyone can help me understand it correctly, thx Find the natural domain of the function algebraically,and confirm that your result is consistent with the graph produced by your graphing utility. note: set your graphing...
  26. F

    How do I correctly notate the domain and range of a function using sets?

    I was just wondering if you could write a functions domain and range with a set? Would it be something like D: {x \epsilon \mathbb{R} | any condtitions} R: {f(x) \epsilon \mathbb{R} | any condtitions} for any function f(x)?
  27. S

    How do I stretch the graph of y=x^3 horizontally by a factor of 3?

    1. Find the domain of the function 5x/8x^2+9 in interval notation. 2. 3. I believe the domain is all real numbers, but do not know what that would look like in interval notation. Could someone show me?
  28. rootX

    Domain of f o g: Finding the Range of Composed Functions

    Homework Statement if f\left( x\right) :=\frac{1}{x-1} for f(x) Doman (x != 1) g\left( x\right) :=\frac{1}{\sqrt{x+1}} for g(x), Domain (x >= -1) so for f(g(x)) the Domain would be (-1,0) U (0, inf)? or do I need to consider other things?
  29. F

    What is the domain of f(x)=ln(ln(ln(x)))?

    Can anyone explain how to get the domain of f(x)=ln(ln(ln(x)))? I am stuck at e^lnlnx > e^o... Thank you.
  30. 0

    Another question about the domain in a compound function

    ¿Could the domain of a compound function be obtained in the same way that non-compound functions? I think the answer is not, like in this example: f(x)=1/x² g(x)=√(2x-6) f(g(x))=1/(√(2x-6))² Recently Hurkyl explained me that (a^b)^c is not always equal to a^bc, although, I've proved this...
  31. 0

    About domain in a compound function

    In my book and in other places, they give this rule to obtain the domain for a compound function: "the domain of (f o g) (x) is the set of all real numbers x such that g(x) is in the domain of f (x)." Then, if f(x)=x^(1/4) and g(x)=x^2 f(g(x)) = (x^2)^(1/4) f(g(x)) = x^(1/2) And applying...
  32. K

    Domain & Range of 2x^2 + 4x - 3

    Find the domain & range of the function. 2x^2 + 4x - 3 I attempted to solved doing the following 2x^2 + 4x = 3 x^2 + 2x = 3/2 (divided by two) (x+1)^2 = 5/2 (completed the square & added one to both sides) (x+1)^2 - 5/2 = 0 So I put the range was (-5/2, infinity), but the book has...
  33. O

    Finding the Range & Domain of y = 24 - 2x

    I'm sorry for this, but what is the range and domain of the following function? y = 24 - 2x y has to be positive (y > 0) and x too (x > 0) How would you solve this? Do you just need a look and then be able to write it down? Or do you need to solve it with algebra? I've found that x can only...
  34. B

    Ideals in an integral domain and Galois theory S_5

    Hi, I've attempted these problems since Sunday morning but I'm still stuck! Please help... These are not homework problems but these are some problems that I'm working on over the summer by myself. Homework Statement 1. Let I_1, I_2,... be ideals in an integral domain. a. If I_1...
  35. M

    What Are the Domain and Range of These Functions?

    Hey here is the question has a few parts to it. Let f(x)= (x-1)^1/2 and g(x)= 2x^2/x^2+1 a) State the domain and range of f using interval notation. b) State the domain and range of g using interval notation. (Hint: At x=0, g is 0. For x(cannot=0) it helps to write g(x)=2/1+1/x^2 and...
  36. P

    If F is a field than does it imply it must also be a Euclidean domain?

    Homework Statement If F is a field than does it imply it must also be a Euclidean domain?The Attempt at a Solution Yes since for any a,b in F. a=bq for some q in R. In fact let q=(b^-1)a. So the remainder which occurs in a ED is always 0. So the rule for being a ED is satisfied in any field.
  37. D

    Finding the Right Web Hosting Service & Domain Name Cost

    Could somebody recommend to me a good web hosting service? Also, how much will a domain name cost me per year?
  38. K

    Find Time Domain Expression for Electric Field e(r,t) of Uniform Plane Wave

    1. Problem Statement Write time-domain expression for electric field e(r,t) of unifrom plane wave with amplitude Eo and frequency f= 1 GHz propagating in free space. The plane wave is propagating in yz plane, 30 degrees from the +y-axis, and 60 degress from -z axis. It is linearly polarized...
  39. P

    Can a subring exist in the same domain as its parent ring?

    Homework Statement If A is a subring of B and B is in a particular domain like a UFD than does it imply A is also in that domain B lives in hence also a UFD?The Attempt at a Solution Z is a ring but not a field. However Z mod p is a field. And Z mod p is a subring of Z. Although Z mod p is a...
  40. S

    What are the domain and range of this function?

    Say I define a function f by sending a well ordered set X to the least element in X. For example, if N is the natural numbers with the usual ordering, then f(N)=1. This function seems to be well defined. I guess its domain is the set of well ordered sets, but this sounds strange. Whats even...
  41. L

    Aaah - sin(wt) - time or frequency domain?

    Aaah! - sin(wt) - time or frequency domain?! hi guys going a bit blank now... been thinking a bit too much about time and frequency domain to a point where I've confused myself a bit... The well known function: f(t) = sin(wt) It is evident that this expression is in the time...
  42. U

    How to become a domain registrar

    How can i become a domain registerater n start selling domains?
  43. Repetit

    Dp/dt in the relativistic domain

    Just a quick question which came to my mind when reading a historical article on Newtons second law. Is \overrightarrow{F}=\frac{d\overrightarrow{p}}{dt} correct in the relativistic domain because the mass is not necessarily constant?
  44. A

    F(g(x)) problem, about the domain.

    Ok, f(x)=x^2 g(x)=sq.rt.(2-x) Problem: f(g(x)) You end up with the answer 2-x but how come you need a domain for the answer? How come the domain is (-infinity,2]?
  45. murshid_islam

    What is the domain of this function?

    suppose x is a real variable. what is the domain of the function \sqrt{{x-3}\over{x-1}}? here {{x-3} \over {x-1}} \geq 0 from this we get the domain to be \left(-\infty, 1\right) \cup \left[3, \infty\right) but if we write the function \sqrt{{x-3}\over{x-1}} =...
  46. S

    Domain of a multivariable eq'n

    Ok, i think i understand this one, but it's giving me a bit of trouble in terms of comprehension, so I thought I'd get some help on it. I need to find and sketch the domain for: f(x,y)= \frac{x^2 + y^3}{x^2 + y^2 -1} The way i see it, that would only be undefined when the denominator...
  47. N

    How Can I Disconnect My Laptop from a Work Domain?

    Hi everyone, After recently moving from my workplace to work remotely using a laptop back in blighty, I found my work-borrowed laptop is part of a network domain. This prevents me from using the network wizard to setup a new connection to the internet through my wireless network at home...
  48. M

    Find the domain of definition and then the limit

    okay i have three limits, i did one and the two others i m stuck... well here 1. limit when x tends to zero of (x-sin(px)) / (x-sin(qx)) p and q are positive integers. for this one i have no idea what to do, i never worked with p or q... 2. limit when x tends to zero of the function...
  49. M

    Finding the Truth Set of a Predicate: 1 <= x^2 <= 4, domain: Z

    Hello everyone! I was wondering if someone could check to see if i did this problem correctly. THe directions are the following: Fid the truth set of each predicate. predicate: 1 <= x^2 <= 4, domain: Z. Where Z stands for integers and <= stands for less than or equal to. The book did...
  50. J

    Solve f(t) = 3: Finding Domain of f(t) = sqrt(t2 - 16)

    If f(t) = sqrt(t2 - 16), find all values of t for which f(t) is a real number. Solve f(t) = 3. All right, I know that I have to find values of t that would make the expression under the radical negative. I was trying to set up an equation to just get the domain. t2 - 16 > 0 this would...
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