1. J

    Surface Area of a Regular Tetrahedron

    How to find the surface area of a regular tetrahedron using calculus? The surface area should be √3 a^2. I tried to do the same approach that MarkFL did for the volume but I could not figure out how to do it with the area!
  2. J

    Regular Tetrahedron

    How to find the volume of a regular tetrahedron using calculus? V = ∫ dV = ∫∫∫ dx dy dz This is what I did first I was thinking to take a cross-sectional equilateral triangle and integrate it from 0 to h, but I could not figure out how to do that. Instead I integrated each variable as...
  3. Z

    Automata Theory regular expressions

    hello , hopefully i made this post in the right section lol. im trying to brush up on my automata for a test and i ran into something thats confusing me. this question asks Which of the following regular expressions denotes the set of all strings over the alphabet {0,1} that contains at least...
  4. C

    Regular Expressions

    Could someone please help me and tell me if this is correct. I need to come up with a regular expression for ... A = {a,b} All strings that contain one or two b's and end with aab I think the answer is (a* b a*) v (a* b a* b a*) aab I am just not positive and I have to be correct
  5. C

    Proving that matrix is regular.

    If A, E are nxn matrices with all elements being real numbers and if (A+E)3=0, then prove that A is regular matrix. I know what it means that matrix is regular, it means that it's determinant is not zero so there exists A-1 and AA-1=E but i don't know how can i prove that all this works for...
  6. H

    Area of regular polygon, proof needed.

    It is given that area of regular polygon = 1/2*perimeter*perpendicular from centre to any side. Can anyone provide proof for this formulae? Thanks.
  7. G

    regular graph

    let it be G=(V,E) bipartite connected graph, r- regular when r>=2. prove that there is a path which his size is at least 2r-1. how can I solve this?
  8. K

    regular polygons-HELP

    ABCD and FCBE are 2 regular polygons. Side BC is mutual. Angel ABE is 70 degrees. What is the sum of the sides of 2 polygons? İmage is in the link below. View image: analitik
  9. H

    How to deal with this problem of regular spherical polygon with max. no. of sides

    A regular spherical polygon has the maximum no. of sides (each as a great circle arc) on a spherical surface with a radius 600 units such that its each interior angle is exactly 177.3 degree. How to evaluate the length of its each side? any help is highly appreciated. thanks...
  10. P

    Scale position of points in a circle so it looks like a regular scaling?

    I have an Art degree, no math involved, so sometimes when doing 3D graphics and envisioning problems, it's hard to search for solutions over the internet since I don't have good pointers for search terms. I'm sure this is a trivial problem with a proper name/solution. Basically I just want to...
  11. Lolligirl

    Showing regular languages are closed under min using DFA's

    Hello all! I think I've got the idea of this question, but am not sure how to create its DFA's: Question: Using DFA’s (not any equivalent notation) show that the Regular Languages are closed under Min, where Min(L) = {w | w ∈ L, but no proper prefix of w is in L}. This means that w ∈ Min(L) iff...
  12. M

    Show that is a regular value

    Good night, my friends, can you help me with these exercise? Let $N$ a $k$-manifold, $X$ a compact $(k+1)$-manifold in $\mathbb R^N$, and $F:X\rightarrow N$ a differentiable map. Let $y\in \operatorname{Reg}(F)\cap \operatorname{Reg}(F|_{\partial X})$ and let $J$ a connected component of...
  13. K

    Regular hexagonal pyramid-maximum volume?

    Guys has six bars in length of 7 meters from which he wants to build a teepee(tipis) in the shape of a regular hexagonal pyramid. Determine the height h (a base b) so that the teepee has as much space as possible.(By space I think they in a real mean volume....) Any idea how to get the...
  14. S

    Area of a Regular Polygon without using Trigonometry

    Can anyone give me some direction on how to find the side length or the area of a regular polygon if I know the apothem or the radius, without using Trigonometry? I need something that works for any amount of sides. Any help would be greatly appreciated!
  15. nycmath

    Statistics and Probabiity Tutor Not Regular Math Tutor

    Here is something you should know. If a student needs help with statistics and probability beyond the high school level, do not hire a regular math tutor. Hire a statistics tutor. You may ask: "Isn't statistics and probability math?" The answer is yes but it is a separate branch of mathematics...
  16. C

    Regular polygon

    Hey Guys, I need some help finding the value of the variable. I know you will need to use sine for this one but I don't know what numbers to use. I know it's a regular polygon with 5 sides so that means each angle is 72. I don't know what the next step would be. State the ratio needed, and...
  17. S

    quick glance at language to determine if regular or not regular

    I was wondering if there is quick way to look at the language to determine if its regular or now or CFG or recursive or recursive enumerable. I found this post "For context free language one quick method is just see the number of comparisions. In the example see n<=m and m<=s. So there are...
  18. topsquark

    Kernal of the left regular action

    The left regular action is defined as follows: Let G be a group and A = G (as sets.) Define \phi : G \times A \to A: g \cdot a \mapsto ga where g is any element of G and a is any element of A. ga is calculated using the group operation in G. The question is to find ker( \phi ). The kernal...
  19. F

    Symmetry group for a regular square based pyramid

    I can figure out e, and three rotations and 4 reflections, which is similar to that of a square. Identify each of your symmetries by a single letter, and use these letters to construct a group table for S(f) is this the same as that of S(square)?? Many thanks.
  20. Nadeshiko

    Diagonals in a regular pentagon

    How many diagonals does a regular pentagon have? Please help me on this problem! I would appreciate steps on how to get the answer or hints!