1. B

    Where can I find Brief notes for first and second order?

    Does anyone have a link or any notes willing to share? I need to refresh my memory on solving 1st-degree equations 2nd with constant coefficients and 2nd with variant coefficients. I'm actually re-reading differentials equations and I believe I'm wasting time since I've already learned them...
  2. idontknow

    Second Order DE

    Solve (x-1)y''-xy'+y=x^2-2x+1 . The solution is y=C_1 x +C_2 e^{x} -x^2 -x -1. any hint or shortcut ? My thoughts are to consider the particular solution y_p as a polynomial, after that we find the other solution by y_2 / y_p = \int y_{p}^{-2}\cdot \mu(x) dx \; where \mu is the integrating...
  3. D

    Order of operation

    My daughter has a math problem that both me and my wife got incorrect due to order of operations. The problem is: (2 3/4 - 3.5) * (-2^2) Solving each term between the brackets = (11/4 - 14/4) * (4) = (-3/4) * (4) = - 12/4 = - 3. The correct answer and method according to the key is as...
  4. L

    Solve the Linear ODE of first order first degree

    Hi all, I'm stuck with this problem. Please help me to identify which method to use. Attaching the question. Thanks a lot for your help.
  5. E

    Probability of Senators From The Same State Consecutively in Alphabetical Order

    Of the 100 senators, the only two consecutively in alphabetical order who are from the same state are Richard (Dick) Durbin and Tammy Duckworth from Illinois. Since last in alphabetical order doesn't loop around to first, there are 99 pairs of senators consecutively in alphabetical order...
  6. D

    Order of Operations with sqrt

    Looking for step by step guide of how to answer. Have a “maybe” answer but it does not look right... struggling with +/- and square root.
  7. M

    Ranking chemical compounds in order of polarity

    Hi! I attached the 3 compounds that I have to rank. I think the order of polarity is: Figure 2 (most non-polar), Figure 3 and Figure 1 (most polar). I'm having a bit of trouble explaining why but I'm going to try my best below: Figure 1 is most polar because it contains carboxylic acid...
  8. A

    Mathematical series & sequences computer programs for printin series in reverse order

    Reference: https://www.google.com/amp/s/edublognss.wordpress.com/2013/04/16/famous-mathematical-sequences-and-series/amp/ Can we write computer programs for the mathematical series & sequences link given above which will print the series in reverse order? Programming languages could be...
  9. A

    Computer program for printing Prime numbers in reverse order.

    https://www.rapidtables.com/math/number/prime_numbers.html I would like to write a computer program which will print prime numbers starting from 100 till 0. i.e. reverse order. Can I get the source code written in any programming language C,C++,Java,C#, Python etc? Thanks & Regards, Prashant...
  10. W

    second order nonlinear differential erquation

    How may I solve the following (d^2 φ)/(dz^2 )+A〖(B+dφ/dz)〗^(n-1)-D dφ/dz=-λ φ: the dependent variable z: the independent variable A, B, D, Lambda are constants n: Unknown constant to remain n during the solution
  11. P

    Academic Guidance Advice on chapter order in my book

    I have written a free e-book with my research (in general topology). Now the book has (among other) chapters "Funcoids" and "Reloids". You don't know what are funcoids and reloids (unless you read my book), but I suppose my general problem formulation does not depend on such details. These...
  12. C

    Solving recurrence of order n

    Hi, I came across this sequence $u_n$ where $u_1=1$ and subsequent terms are given by the recursive formula $$u_{n}-\sum_{k=1}^{n-1}T(n,k)u_{k}=f(n)$$ where $T(n,k)$ are real non constant coefficients and $f$ is a given function. Is there a general method to solve this equation? ... Thanks...
  13. D

    Lexicographic Order Topology Vs Subspace Topology

    Is the Lexicographic Order Topology on the ordered square [0, 1] X [0, 1] the same as the subspace topology it inherits from R X R?
  14. S

    Q: Let S = {1,2,5,6} Define a relation R on S of at least four order pairs

    Q: Let S = {1,2,5,6} Define a relation R on S of at least four order pairs, as (a,b) ∈ R iff a*b is even (i.e. a multiplied by b is even).
  15. D

    How to change the order of integration in 3D?

    I have been working on a problem that requires me to integrate in the following way: $$\int_{0}^{\infty} \int_{0}^{y} \int_{0}^{y-x} f(x,y,z)\ dzdxdy$$ I would like to change the order of integration, with dz going last. For the dydxdz option, I've got: $$\int_{0}^{\infty}...
  16. M

    From disorder to order

    This is awesome LCepT9N5Slw
  17. I

    Fractions in Order of Operations

    When using order of operations, do you simply put the top part of the fraction next to the bottom part of the fraction with a division sign in between them, or do the upper and lower parts of the fraction act as equations in parentheses? I have been simply rewriting the fraction as a division...
  18. V

    First Order Separable Equation Examples

    I'm looking for inspiration. I need examples of interesting first order separable equations. If they have a real-life application, that's all the better.
  19. J

    My elegant formula for the Harmonic Numbers of order k

    I'm looking for someone who can "introduce" me to the arXiv.org site, so I can upload a paper that demonstrates my elegant formula for the Harmonic Numbers of order k. Because I no longer have a university email, and haven't published in my undergrad years, there's this little obstacle that you...