1. A

    Check whether two points are symmetrics/asymmetrics

    I'm working on an Android app that lets a group of children draw whatever they want in a specific area. I need to check whether the lines and figure that they draw are symmetric. The problem is that since the app is designed to let them draw freehand, I don't know how to compare the lines by...
  2. idontknow

    Need to check the method (DE)

    Equation : y’’=y. Add both sides +y’ then substitution as y’+y=t. t’=t. Is this way correct?
  3. M

    Check my understanding (line integrals)

    Ok so if I'm understanding correctly, line integrals integrate over a curve (C) unlike over a region on the x or y axis like a regular integral would. So you have a curve represented by the vector function r(t) = C = x(t) i + y(t) j let's take a region along that curve that can be defined by...
  4. MikeAndIke

    Homework Check: Concavity and Second Derivative Test

    Please tell me what I need to correct, otherwise thanks for helping to check my Calculus work. Attachment is below, please check to view my answers.
  5. N

    Check, for constructing nice set of linear equations

    Hi Well, I was struggling with solving these linear equations for days. more accurately, It solved but the answers do not check with what I have, so want to find where I have mistaken. It would be appreciated if you can check with me that my understanding is correct for the problem. (do not...
  6. A

    Computer program to check a floating or decimal point palindrome number.

    Reference : Write a computer program to check whether a floating or decimal point number is a palindrome? Example Input : 45.54 Output : 45.54 The inputted number is a floating or decimal point...
  7. Z

    EigenValues and differential equations.. Please check my math

    Suppose P is the projection matrix onto the 45◦ line y = x in R2. Its eigenvalues are 1 and 0 with eigenvectors (1, 1) and (1,−1). If dy/dt = −Py (notice minus sign) can you find the limit of y(t) at t = ∞ starting from y(0) = (3, 1)? My Solution: dt/dy = -Py, the eigenvalues are now...
  8. Monox D. I-Fly

    Please Check My Work Regarding Limit

    The value of \lim_{x\to\frac{1}{2}\pi}\frac{1-\sin x}{x-\frac{1}{2}\pi} is .... a. -2 b. -1 c. 1 d. 0 e. 2 What I did: \lim_{x\to\frac{1}{2}\pi}\frac{1-\sin x}{x-\frac{1}{2}\pi} =\lim_{x\to\frac{1}{2}\pi}\frac{\sin\frac{1}{2}\pi-\sin x}{x-\frac{1}{2}\pi}...
  9. S

    Set notation with empty set

    Let A = ∅, B = {7, 8, 9, 1, {∅}}. For each of the following, state whether the statement is True or False. (a) ∅ ∈ A = true (b) A ⊂ B = false (c) P(A) ∈ B = false (d) B ⊆ A = true (e) A ⊆ B = true (f) A ⊆ ∅ = false
  10. Z

    Please check my math..

    Find the volume of the region B bounded above by the sphere x^2 + y^2 + z^2 = a^2 and below by the plane z = b, where a > b > 0. My solution \int_{0}^{2 \pi } \int_{0}^{ arccos( b/a ) } \int_{0}^{ a - b/cos \phi } \rho^2 sin \phi ~d \rho ~d \phi ~d \theta
  11. P

    Searching Win prgm to generate and check prime numbers

    I am searching a fast Windows programs which let me - generate (starting from 3) - factorize (a user entered) prime numbers. If possible these functrion should be provided by ONE program. If possible the program should use multiple CPU cores/threads. Who can recommand me...
  12. E

    would anyone check my answer

    Problem 19. An open rectangular box with square ends is fitted with an overlapping lid which covers the top and the front face. Determine the maximum volume of the box if 11m² of metal are used in its construction. Would the answer be 4/5m³?
  13. G

    Could someone check this expected value algebra?

    I attached a picture with some lines of algebra that don't quite make sense to me. Actually, the only jump between lines I'm confused about is line 1 to line 2. I think there should be an n^2 pulled out instead of an n. Could someone tell me if I'm correct or if not explain in more basic algebra...
  14. F

    Check answer for absolute value equation

    Could someone please check that my answer is correct for the attached absolute value equation? My textbook only has answers for odd numbered questions.
  15. M

    Answer check - Boolean algebra

    Hey guys can someone's tell me if this is correct?
  16. A

    Can someone check my derivation for 2-D Finite Difference Fourth Order Equilibrium

    I made a post about this derivation earlier this weekend and spent some time deriving it and I believe I have the correct solution. Attached is the derivation. I would appreciate it if someone could check my work and let me know their thoughts. Thanks!
  17. B

    Check if $y = x^3 - 3x$ is injective.

    Hi, I have this function: $f(x) = x^3 - 3x$ To check if it is injective, following the definition of injective, I tried this: $a^3 - 3a = b^3 - 3b \\ a^3 - 3a -b^3 + 3b = 0 \\ (a-b)(a^2+ab+b^2)-3(a-b) = 0 \\ (a-b)(a^2 + ab+b^2-3) = 0$ but, I don't know how to continue. Please...
  18. B

    Check if equation defines an operation on the set of integers.

    Hi, I have the following exercise, it is required to check if the following equation defines an operation on the set of integers, and if so, check if it is associative, commutative and identity element. $m * n = mn + 1$ I have taken $m = 2, n = 3$ $2*3 = (2 \cdot 3) + 1 = 6 + 1 = 7...
  19. N

    Check if integral converges

    Hi guys, I've to verify if \int_{1}^{+\infty} \frac{e^{-x}}{\sqrt x}dx converges. I use the convergence criteria: \frac{e^{-x}}{\sqrt x} \leq \frac{1}{\sqrt x}. The exponent of x is 1/2 , for the convergence criteria this integral should not converge, but standing to wolfram (and to the book)...
  20. T

    Vector projection ans check and derivation check

    Hi all can someone please just have a look at my derivation for projection vectors and the ans to this question please. I have attached photos with my working big thanks in advance. Find the vector which is obtained as the projection of the vector A=(3,5,1) on the direction...