1. M

    Interesting math problem

    Hi All, To better describe the problem I have uploaded here: Feel free to ask any questions. Any help is appreciated!
  2. J

    Interesting Mathematical Find.

    Hello, I wanted to share something I find interesting with you all. So, I was experimenting with making up math formulas, I like to do that in my spare time. I found something VERY interesting, (at least to me,) while doing this. I was trying to find out on my own a regular polygon...
  3. D

    Interesting triangle headache

  4. M

    Riemann's Sum Problem

    Brief Overview What I've done so far: The Question If the safety capacity for the benign use of a camping gas lamp inside a confined space is (104÷5) m^3, calculate whether it would be safe to use the lamp within the lightweight ‘pop-up’ tent. I know the height of my tent is...
  5. O

    Please help with this interesting sum proof

    Hi, I am trying to prove the following identity. I obviously can't see something here. \sum_{1}^{n}\frac{\prod_{r=1}^{n-1}(y_k-z_r)}{\prod_{1<=r<=n, r\ne k}(y_k-y_r)}=1 Where y_1,y_2,...y_n are different numbers and z_1,z_2,...z_{n-1} is set of any numbers. I obviously can't see something...
  6. Z

    interesting probability question

    Newly borned babies with probability of 0.51 are boys, girls with probability of 0.49 and gender is independent across births. You meet a couple who tell you they have two children, and you ask whether they have any daughers. If they do (i.e. they have one or two girls), what is the...
  7. B

    Quartic equations - interesting problem

    I can solve all square and cubic equations with complex coefficients. For quartic I use method from book "Solution of cubic and quartic equations" - S.Neumark. For Ax^4+Bx^3+Cx^2+Dx+E In this method we first solving auxiliary cubic equation: 1 -2Cx^2+ (C^2 + BD - 4AE)x -(BCD - BBE - ADD)...
  8. Ould Youbba

    Interesting Circle Question

    Salam ! This is your Christmas gift from me :D. Let O be the center of a circle. A, B, C and D are points of this circle such that the straight lines (AC) and (BD) are perpendicular and secant in I. Let H be the midpoint of the segment [BC]. In the triangle IAD, let J be the foot...
  9. M

    Interesting thoughts on square roots

    One thing I always figured was really strange was roots of negative numbers and that was handled in designing math language. One thing I've figured out recently is that roots are set up to ignore a simple fact, they are two dimensional numbers being reduced to one dimension. Well two...
  10. X

    interesting sets of equations

    in real numbers sets of equations \begin{align*} x^{2}y+2=x+2yz \end{align*} \begin{align*} y^{2}z+2=y+2zx \end{align*} \begin{align*} z^{2}x+2=z+2xy \end{align*}
  11. C

    Need help finding fomula for interesting function

    The tangent of f(x) intersects the y axis at 1 - x. The function in question is shown in green on the dark plot, the blue line is just showing the tangent intersecting the y axis at 0.6 when x = 0.4 as a single example. The light plot shows how the curve is constructed. Here a coarse curve is...
  12. M

    An interesting conundrum about area to line ratios

    I realized that there is a problem with how area is measured. To illustrate, Consider a Post-it note. If you look at it abstractly, the ratio between the edge and the area remains the same when we measure it because simply measuring the note does not change the note itself, but on the...
  13. P

    Very interesting System

    Can you help me get to the solutions of the system and show me the way of working it out? Good luck. :D
  14. D

    interesting prime numbers

    I will define the mirror of n : the mirror of 532 is 235, the mirror of 437 is 734 etc. We will say that the nth prime number is the prime in place n. I will define interesting primes as the prime in place n, which his mirror is the prime in place of the mirror of n. Examples: 2 3 5 7 11...
  15. T

    Interesting finding about pi and scientific constants

    Dear all, I explored the value of pi up to 10 million digits with the following link Pi - 10 Million Digits @ From here, I realized that it included many scientific constants. Below are some examples • …1618033… Where 1.618033 ~ golden ratio to be used in design...
  16. D

    Interesting Loan case...

    A loan is obtained, at monthly payments, over 12 months. The amount that went to principal at 3rd pay't = 804.34 The amount that went to principal at 7th pay't = 837.00 How much was borrowed, at what rate, at what monthly pay't? This'll probably wake up Sir Jonah :cool:
  17. A

    Interesting array

    I generated array and I wanted to check is it exactly random: 14,8 23 28,2 18,4 21,8 19,8 32,6 21,4 23,2 20,4 23,4 21 22,4 21,6 29,8 14,2 10,8 21,6 23,6 30 24,2 20,8 19 21,2 15,6 23,6 21,8 24,2 30,2 15,6 20 16,8 20,8 25 11,4 26,2 30,6 15,8 14 23,4 28,2 22 19,8 20,8 22,6 17,2 26,2 28,4 32,4 22
  18. J

    Interesting problems

    Hello, I am a user that recently signed up. I was wondering if any of you had odd or just complicated equations. An example could be as simple as x^3+y^3=z^3, (not sure whether this site supports exponents in text) or something harder. Feel free to post anything you've found or would like to share.
  19. K

    Has anyone analyzed non prime numbers? Exponents seem interesting.

    Hi, I just came to this idea after watching a video about Prime Numbers. I started factoring numbers from the lowest onwards and then simplified it with exponents. (I started with 2 despite it being a Prime) __| 2 3 5 7 11 13 02| 1 04| 2 06| 1 1 08| 3 0 09| 0 2 10| 1 0...
  20. P

    Interesting thing about graphs (adding x! to formulas)

    I was just playing with a graph drawing software and noticed something very interesting. The graph of y = x! , when going further into negative X, turned into a straight line with infinitely long vertical lines coming out of it to both positive and negative Y at every whole number. Basically it...