Partial Definition and 1000 Threads

  1. D

    How much gas is released given partial pressure

    Homework Statement The solubility of N2 in blood at 37 degree and at a partial pressure of 0.8 atm is 5.6 x 10-4 mol/L? a deep sea diver breathes compressed air with the partial pressure of N2 equal to 4 atm. Assume that the total volume of blood in the body is 5 L. Calculate the amount of N2...
  2. K

    Mathematica partial differentiation weirdness

    I am checking my homework with mathematica, but sometimes when I write stuff like D[(x/((x^2 - y^2)^0.5)), y] , which is supposed to give me the partial derivative of x/((x^2 - y^2)^0.5) with respect to y, i get answer like: (1. x y)/(x^2 - y^2)^1.5 which is right, except for the...
  3. T

    Partial Derivatives of Vectors and Gradients

    I was reading a section on vector fields and realized I am confused about how to take partials of vector quantities. If V(x,y)= yi -xj, I don't understand why the \partialx= y and the \partialy= -x. The problem is showing why the previous equation is not a gradient vector field (because the...
  4. F

    Integration of Rational Functions by Partial Fractions

    Homework Statement Evaluate the integral. (Remember to use ln |u| where appropriate.) ∫(x^3 + 36)/(x^2 + 36) Homework Equations The Attempt at a Solution A little bit confused about arriving at the solution for this problem. I get stuck a little ways in. Any help would be...
  5. M

    What are the partial pressures of H2, Br2, and HBr at equilibrium?

    Homework Statement at 1000K, Kp=1.2*10^6 and Delta H = -101.7 kJ for the reaction H2(g)+ Br2(g) <-->2HBr. A 0.952 mol quantity of Br2 is added to a 1.00L reaction vessel that contains 1.25 mol of H2 gas at 1000K . What are the partial pressures of H2 ,Br2 ,HBr and at equilibrium?Homework...
  6. B

    MHB Partial derivatives economics question

    If a and b are constants, compute the expression KY'(K) + LY'(L) for Y = AK^a + BL^a Y'(K) means partial derivative with respect to K by the way. The answer in the book is KY'(K) + LY'(L) = aY I'm not sure what they did or what they're asking :/
  7. jinksys

    Partial Fraction Decomp with a constant

    This is throwing me through so many loops. I have the equation 1/(x^3 + xa^2). I can not for the life of me decompose this equation. I use 1(x^3 + xa^2) = A/x + (Bx + C)/(v^2+a^2) I can get A=1/a^2, but from there progress stops. All examples on the internet and books only have...
  8. S

    Partial differentiation question. Would all three methods work?

    I'm attaching the question and solution. I'm talking about the first part since the second part is the same just with different variables and stuff. I get what the solution is saying but: 1) What if I computed a Jacobian, with F = x^2 + xy + y^2 - z = 0 G = 2r + s - x = 0 H = r - 2s - y...
  9. K

    What is the Partial Derivation Question in Mary Boas's Book?

    From Mary Boas's book, chapter 4. Z = x^3 -e^xy 1- Z(x) = 3x^2 y - ye^xy make sense according to derivation rule d(e^u)/dx = e^u.u` 2-Z(y) = 3^x - xe^xy make sense too. 3-Z(y)x)) = 3x^2 - e^xy - xye^xy where e^xy came from ?? Thank you.
  10. M

    Second-Order Partial Derivative of a Parametric Function

    The problem is from an online homework assignment. I know it's probably fairly simple, but my brain isn't grasping it right now for some reason.[The Problem] We know: r(t) = <3t2 - 8t + 3, -9t2 + 2t + 7> And we are asked to find d2y/dx2.[Background Information] My understanding of d2y/dx2...
  11. E

    Is There a General Formula for this Partial Fraction Function?

    Hello, Is there any general formula for the partial fraction of the following function: \frac{1}{(ax_1+1)(ax_2+1)\cdots (ax_L+1)} I can work for L=3, but it get involved for larger L! Thanks in advance
  12. MathWarrior

    Seperable Differential Equation Invovling Partial Fractions

    y' = (3+y)(1-y) y(0) = 2 Attempt to solve: \frac{dy}{dx}=(3+y)(1-y) (3+y)(1-y)dy = dx \int(3+y)(1-y)dy = \int dx Partial Fractions: \frac{A}{(3+y)} + \frac{B}{(1-y)} A(1-y)+B(3+y) Let y= 1 or -3 A = 1/4 B = 1/4 \frac{1}{4}\int \frac{1}{(3+y)} dy + \frac{1}{4}\int...
  13. xortan

    How to Approach Proving a Partial Derivative Homework Problem?

    Homework Statement I have attached a picture of the problem. The question is the first one. Homework Equations The Attempt at a Solution I tried subbing u and v into the right hand side of the equation. I expanded and simplified but I do not think that is the right way to go...
  14. B

    Integration by partial fraction problem (∫dx/x(x^2 + 4)^2)

    Homework Statement I came across a problem that I can't solve and it is ∫dx/x(x^2 + 4)^2 Homework Equations None The Attempt at a Solution So I'm pretty sure this is to be solved by partial fraction since I am on a chapter on Integration by partial fraction. so I started with...
  15. S

    I'm having major difficulties with partial differentiation using the chain rule

    This is another problem than I've been stuck on for a long time and I tried reading and watching videos but I only find first order partial differentiation with more than two variables or higher order partial differentiation with only two variables. (I'm not calling f a variable but I am calling...
  16. A

    How to integrate partial differential eqn

    Homework Statement im not sure the elegant way to put it, i need to integrate this somehow (ie, throw over the dt and integrate each side) but that squared is really tripping me up. is there a trick i should be using? -g(cos(x))=r(dx/dt)^2 Homework Equations The Attempt at a...
  17. S

    I can't seem to do this with partial fractions

    Homework Statement \frac{x}{(x+4)^{2}} Homework Equations The Attempt at a Solution I make the integrand equal to the following: \frac{A}{(x+4)}+\frac{Bx+C}{(x+4)^{2}} Then after finding a common denominator I get x = A(x+4)^{2}+(Bx+C)(x+4) But that cannot be...
  18. F

    Partial Derivative: Finding the vector on a scalar field at point (3,5)

    Homework Statement A scalar field is given by the function: ∅ = 3x2y + 4y2 a) Find del ∅ at the point (3,5) b) Find the component of del ∅ that makes a -60o angle with the axis at the point (3,5) Homework Equations del ∅ = d∅/dx + d∅/dy The Attempt at a Solution I completed part a: del ∅ =...
  19. Telemachus

    MHB Partial Differential Equation: Is There an Easy Way to Solve This?

    I have this partial differential equation that I have to solve, and I thought that perhaps there was an easy way of solving this, like finding an equivalent differential for the right hand side of the equation, on such a way that I could get a simple differential equation, and then just...
  20. E

    Partial Derivatives, and Differentiable

    Homework Statement I want to show that the partials exist for a certain function. Homework Equations My book says that if a function f is differentiable at a point x then the partial derivatives exist. The Attempt at a Solution Rather than showing f is differentiable, I am...
  21. Telemachus

    What is an easy way to solve this partial differential equation?

    Hi there. I have this partial differential equation that I have to solve, and I thought that perhaps there was an easy way of solving this, like finding an equivalent differential for the right hand side of the equation, on such a way that I could get a simple differential equation, and then...
  22. E

    Partial Fractions Solving: Denominators having degrees more than 2

    I just want to know if there is now a way to solve fractions like which had a variables that has a degree more than 2 in its denominator. I know that denominators having degrees of 2 could be solved using (Ax + B)/(x2+a). But how about denominators like (x3+a) and so on?
  23. C

    How do we show that 2.2.19 and 2.3.21 are equal in this textbook?

    In this textbook, how exactly are 2.2.19 and 2.3.21 equal? http://i.imgur.com/LrcXE.png
  24. S

    Partial Fractions (Laplace Transform, complex roots)

    Hello all, Say one wants to find the inverse Laplace Transform of a function, and the method for attaining the solution is executed via partial fractions. Do the real numbers go with the complex numbers when determining the constants of partials? Perhaps this is wordy. I'll provide a theoretical...
  25. U

    Partial derivative of function w.r.t. the percent change of the variable

    Homework Statement Rewrite this in terms of f, f, ∂f/∂x, and x: ∂f(x,y)/∂(%Δx) = ∂f(x,y)/∂(d log(x) ) Homework Equations ∂(%Δf(x,y))/∂(%Δx) = ∂logf(x,y)/∂log(x)= ∂f(x,y)/∂x*x/f(x,y). ∂f(x,y)/∂log(x)=x∂f(x,y)/∂x The Attempt at a Solution I found that (%Δx) can be written as...
  26. B

    Partial Pressure: Understanding CHCl3 & (C2H5)2O

    Hello everyone, I'm trying to understand more about how partial pressure works and how to use chemical activity equation. My reference text uses the following example: Note1: A solution is prepared by mixing 2 moles of CHCl3 (chloroform) and 3 moles of (C2H5)2O (diethyl ether). Note2: The...
  27. M

    Partial Derivative f(x,y')=1: Why & True?

    let f(x, y') = x + y' where y' = dy/dx then is it true, and why, that the partial derivative of f with respect to y' = 1 in this case we consder dx/dy' = 0, as if they are independent of each other.
  28. C

    Partial integration of the function f = 1

    Given a function z(x,y), is the following expression valid: ∫(1)∂z = z Does this even make sense? I came up with this in my differential equations class, but I'm not sure if it actually means anything.
  29. K

    Partial Pressures of an Ideal Gas Mixture Containing Water Vapor

    Homework Statement A gas mixture of 0.13 mol NH3, 1.27 mol N2, and 0.025 mol H2O vapor is contained at a total pressure of 830 mm Hg and 323 K. Calculate the following: (a) Mole fraction of each component. (b) Partial pressure of each component in mm Hg. (c) Total volume of mixture in m3...
  30. Z

    Stationary Point after Partial Differentiation

    Homework Statement A question in a book has partially differentiated a function f(x,y) = x^2 + 8xy^2 + 2y^2 df/dx = 2x + 8y^2 = 0 at stationary point (eqn 1) df/dy = 16xy + 4y = 0 at stationary point (eqn 2) Homework Equations The Attempt at a Solution It then states...
  31. R

    Proving me ? partial orders :hasse diagrams

    partial orders :hasse diagrams theorem : if [A,R] is poset and A is finite , then A has both a maximal and a minimal element A={a1,a2,a3...an} but i know prove it is maximal , but i not know how i prove it is minimal ? please answer ?
  32. B

    Function in terms of its partial derivatives

    Hi, I remember having read in basic calculus that the following is true, but I don't know what this property is called and am having a hard time finding a reference to this. d u(x,y) = \frac{\partial u}{\partial x} dx + \frac{\partial u}{\partial y} dy Ques: Is this true ? Is this true for...
  33. I

    Proving a Partial Differential Equation: Is the Sum of Second Derivatives Zero?

    Homework Statement Hi I need some help in proving that \partial^2 V / \partial x^2 + \partial^2 V / \partial y^2 = 0 , when V = 1/2ln(x^2+y^2) Homework Equations The Attempt at a Solution For \partial V / \partial x here's what I get: (1/x^2+y^2) *2x*1/2 = x * (x^2+y^2)^-1 and for \partial V...
  34. R

    Maple - LU Factorization with Partial Pivoting

    [b]1. I am asked to write a procedure that will inverse square matices using LU factorization with partial pivoting. [b]2. I am also told that the procedure should return the inverse matrix and report an error if it cannot do so. [b]3. So far I've come up with the code below but...
  35. G

    Chemistry Partial pressure and moles problem?

    Homework Statement Here is the problem: Carbon monoxide and oxygen are kept at exactly 300 K in separate chambers of the apparatus shown below. When the stopcock is opened, the combustion reaction begins and is allowed to proceed to completion, while being maintained at exactly 300 K...
  36. nomadreid

    Are implicit and partial differentiations related?

    I was working two different but superficially related problems, and noticed that if I did something that is generally not allowed, the results were connected by a negative sign. My questions are whether this will always turn out this way, and if so, why. The two problems were (A)...
  37. Saladsamurai

    Partial Differential EQs for Engineers

    Hello all! :smile: I have searched this, but I am still looking for additional input. I am an engineer and I want to self-study PDEs. I looked at Farlow's text and though it is nice from an applications standpoint, I think that it is not 'mathy' enough for me. Don't get me wrong, I am not the...
  38. W

    Partial Reflection-Partial Refraction

    Homework Statement Can partial reflection-partial refraction occur with all waves (ie. other than light)? Homework Equations The Attempt at a Solution My textbook constantly refers to light and apparently so does Google. "For still larger incident angles there is no...
  39. N

    Equality of mixed partial derivatives of order >2

    I know that for any C2 function, the mixed second-order partials are equal, and I see that this should extend inductively to a statement about the kth partials of a Ck function, but I am having trouble figuring out exactly how this works. For example, take f:ℝ2 → ℝ . fxxy=fxyy is not true...
  40. 5

    Implicit partial differentiation functional det[]

    Hello! I was wondering how I could find the following derivatives from the given function using Jacobian determinants. f(u,v) = 0 u = lx + my + nz v = x^{2} + y^{2} + z^{2} \frac{∂z}{∂x} = ? (I believe y is constant, but the problem does not specify) \frac{∂z}{∂y} = ? (I...
  41. M

    Finding the nth Partial Sum for a Series Involving Floor and Mod Operators

    Given some natural number n find the nth partial sum for: \displaystyle\sum_{k=0}^{\lfloor log(n) \rfloor} \lfloor \frac{n}{10^k} \rfloor I find this question really difficult! If anyone could help, it would be greatly appreciated. Thanks in advance!
  42. S

    Partial Derivative of Van der Waals Equation

    Given that the Van Der Waals equation is (p + (an^2)/v^2)(v-nb)=nRT where n,a,R and b are constants... How to we find the derivative of p wrt v ? How to find the derivative of p wrt T without further differentiation ?? Can anyone teach me how to do this question ? Sincerly thanks~
  43. S

    Second Derivative Test for Partial Derivatives

    Hi there, just wanted to make a clarification before my final exam. The second derivative test for partial derivatives (or at least part of it) states if D = ∂2f/∂x2 * ∂2f/∂y2 - (∂2f/∂x∂y)2 and (a,b) is a critical point of f, then a) if D(a,b) > 0 and ∂2f/∂x2 < 0, then there is a local...
  44. K

    Partial Derivative of f(x,y) at (0,0)

    Homework Statement The question asks: f(x,y) = 3xy+5y^3/[x^2+y^2] when (x,y) =! (0,0) f(x,y) = 0 when (x,y) = (0,0) what is df/dy at (0,0)? Homework Equations The Attempt at a Solution I'm not sure what the answer is. At 0,0 f(x,y) is 0, so it's simply a point and the...
  45. T

    Maple Maple Partial Sum Problem: How to Find the Sum of a Series on Maple 13

    So I'm trying to figure out how to find that partial sum of a given summation of a series on maple 13. Iv tried looking all over the internet for answers to my problem, but no site seems to answer my problem. I am trying to find the sum of a series. When i plug in 1/x^2 and evaluate I get the...
  46. J

    PARTIAL oxidation of methane as energy source

    Methane from natural gas could be a great source of energy (eg. in thermoelectric plants), but the need to curb CO2 emissions stands in the way. I wonder whether one could get useful energy from some partial combustion reaction of CH4, that yields H2O plus some carbon-containing solid that...
  47. D

    Q on Second partial derivative test for functions of n variables

    Hi, I would like to confirm that I have understood this correctly. The steps to find local maxima/minima of a function f(x1, ... , xn) are: 1) We find all the stationary points. 2) We form the Hessian matrix and calculate the determinants D1, D2... Dn for a stationary point P we want to check...
  48. M

    Implicit second order partial derivative

    Homework Statement Given that the surface (x**5)(y**2)+(y**5)(z**3)+(z**3)(x**2)+4xyz=7 has the equation z=f(x,y) in a neighbourhood of the point (1,1,1) with f(x,y) differentiable, find the derivatives (∂**2f)/(∂x**2) at (1,1) Homework Equations The Attempt at a Solution I...
  49. T

    Difference between convergence of partial sum and series

    I am a little confused as to notation for convergence. I included a picture too. If you take a look it says "then the series Ʃan is divergent" Does the "Ʃan" just mean the convergence as to the sum of the series, or the lim an as n→ ∞ nth term? I believe it is the sum of the series but I...
  50. 1

    A good book on Differential Equations and Partial Differential Equations?

    At my school, Physics majors are the only ones who HAVE to take PDE, math majors and engineers have the option as an elective, but none of them do that because it has the reputation of being the most difficult math course at my school. I'm going into Calc III in the spring, then DE is next...
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