Facebook Page
Twitter
RSS
+ Post New Thread
Page 1 of 58 1231151 ... LastLast
Threads 1 to 30 of 1737

Forum: Challenge Questions and Puzzles

Have a challenging question or puzzle you want to share with the community? Post it here (homework questions do NOT belong here).

  1. Sticky Thread Sticky Threads

    • Replies: 2
    • Views: 2,026
    October 15th, 2017, 16:11 Go to last post
  1. Normal Thread Normal Threads

  2. irrational number

    Started by kaliprasad, February 21st, 2018 11:02
    $sin, 10^circ$, irrational, number, show
    • Replies: 8
    • Views: 140
    Yesterday, 13:05 Go to last post
  3. Find the antiderivative

    Started by lfdahl, February 21st, 2018 17:42
    $fracsqrt2-x-x^2x^2$, antiderivative, find, fracsqrt2-x-x^2x^2, function
    • Replies: 0
    • Views: 40
    February 21st, 2018, 17:42 Go to last post
  4. Evaluate the product of sines

    Started by lfdahl, February 12th, 2018 14:58
    angles, degrees, evaluate, product, sines
    • Replies: 5
    • Views: 255
    February 18th, 2018, 11:56 Go to last post
  5. Prove the limit

    Started by lfdahl, February 9th, 2018 09:40
    1.$$, limit, n-1^n-1+n^nn^n, n-1^n-1n^n, prove
    • Replies: 2
    • Views: 177
    February 11th, 2018, 15:15 Go to last post
  6. A good number challenge

    Started by lfdahl, February 9th, 2018 09:16
    $m$, $n$, good, number, set
    • Replies: 2
    • Views: 147
    February 11th, 2018, 12:47 Go to last post
  7. Equilateral triangle - probability calculation

    Started by lfdahl, February 1st, 2018 17:27
    • Replies: 1
    • Views: 128
    February 9th, 2018, 15:03 Go to last post
  8. Sum to product inequalities

    Started by lfdahl, January 15th, 2018 17:26
    $1-alpha_11-alpha_2, 1-alpha_n, geq, implies, sum
    • Replies: 5
    • Views: 226
    February 4th, 2018, 15:12 Go to last post
  9. Root function inequality

    Started by lfdahl, January 23rd, 2018 15:18
    cdot, non-negative, numbers, real, root
    • Replies: 4
    • Views: 216
    February 4th, 2018, 00:29 Go to last post
  10. Integral challenge

    Started by lfdahl, January 29th, 2018 16:36
    $$int_0^1, challenge, definite, evaluate, integral
    • Replies: 4
    • Views: 240
    February 1st, 2018, 17:00 Go to last post
  11. Find the exact sum of the series ...

    Started by lfdahl, January 23rd, 2018 14:21
    $$s, exact, find, series, sum
    • Replies: 5
    • Views: 251
    January 29th, 2018, 01:56 Go to last post
  12. Weird function challenge

    Started by castor28, January 16th, 2018 05:03
    2 Pages
    1 2
    $mathbbr$, discontinuous, function, interval, sense
    • Replies: 12
    • Views: 347
    January 26th, 2018, 09:16 Go to last post
  13. Dice rolling - running total probability

    Started by lfdahl, January 19th, 2018 13:57
    1006$, dice, rolled, running, total
    • Replies: 8
    • Views: 262
    January 23rd, 2018, 10:24 Go to last post
  14. Determine the integer with 3 specific properties

    Started by lfdahl, January 12th, 2018 16:56
    $n$, determine, digits, integer, properties
    • Replies: 7
    • Views: 178
    January 15th, 2018, 14:41 Go to last post
  15. Liars and truthtellers

    Started by castor28, January 4th, 2018 05:23
    inhabitants, island, knaves, number, yes-no
    • Replies: 1
    • Views: 102
    January 14th, 2018, 05:06 Go to last post
    • Replies: 2
    • Views: 133
    January 13th, 2018, 14:58 Go to last post
  16. Find the smallest A satisfying the inequality

    Started by lfdahl, January 11th, 2018 14:46
    find, number, real, satisfying, smallest
    • Replies: 3
    • Views: 152
    January 13th, 2018, 00:53 Go to last post
  17. Sum of squared cosines is in fact independent of ...

    Started by lfdahl, January 9th, 2018 15:14
    cube, denote, independent, sphere, ^2angle
    • Replies: 2
    • Views: 140
    January 11th, 2018, 14:34 Go to last post
  18. Prove the nested radicals identity

    Started by lfdahl, January 9th, 2018 18:24
    identity, nested, prove, sqrtn+sqrtn-, [sqrtn
    • Replies: 4
    • Views: 188
    January 10th, 2018, 15:25 Go to last post
  19. Find the maximal value of the sum

    Started by lfdahl, October 8th, 2017 14:36
    find, maximal, numbers, real, satisfying
    • Replies: 4
    • Views: 230
    January 9th, 2018, 05:27 Go to last post
  20. Find the maximal number of subsets, k.

    Started by lfdahl, January 1st, 2018 15:04
    $a_i, find, leq, maximal, subsets
    • Replies: 1
    • Views: 107
    January 7th, 2018, 14:30 Go to last post
  21. Evaluate the integral

    Started by lfdahl, January 1st, 2018 15:16
    cdot, cos, evaluate, integral, [int_0^2picos
    • Replies: 9
    • Views: 335
    January 7th, 2018, 14:17 Go to last post
  22. [SOLVED] Polynomial challenge

    Started by castor28, December 21st, 2017 05:39
    $fr=p$, $q$, $r$, integers, polynomial
    • Replies: 3
    • Views: 186
    January 2nd, 2018, 00:24 Go to last post
  23. Upper and lower bounds of a binary number

    Started by lfdahl, December 29th, 2017 12:55
    $9$, digits, lower, number, upper
    • Replies: 4
    • Views: 123
    December 30th, 2017, 16:08 Go to last post
  24. 2 x 2 matrix puzzle

    Started by lfdahl, December 29th, 2017 12:38
    beginpmatrix, endpmatrix], integer, matrix, [s^n=
    • Replies: 4
    • Views: 131
    December 29th, 2017, 18:09 Go to last post
  25. Sum of polynomial coefficients inequality to be proved

    Started by lfdahl, December 29th, 2017 12:29
    $pqx$, $qx, polynomial, real, sum
    • Replies: 2
    • Views: 88
    December 29th, 2017, 17:55 Go to last post
  26. high school geometry

    Started by solakis, December 26th, 2017 19:56
    circle, examination, geometry, high, school
    • Replies: 2
    • Views: 107
    December 27th, 2017, 05:00 Go to last post
  27. Trigonometric sum identity

    Started by lfdahl, December 16th, 2017 16:21
    identity, prove, sum, trigonometric, [sum_j=1^n-1csc^2left
    • Replies: 2
    • Views: 162
    December 22nd, 2017, 16:16 Go to last post
  28. Definite integral challenge

    Started by lfdahl, December 17th, 2017 18:19
    $$int_0^piln, challenge, definite, integral, prove
    • Replies: 2
    • Views: 124
    December 18th, 2017, 15:27 Go to last post

Thread Display Options

Use this control to limit the display of threads to those newer than the specified time frame.

Allows you to choose the data by which the thread list will be sorted.

Order threads in...

Note: when sorting by date, 'descending order' will show the newest results first.

Icon Legend

Contains unread posts
Contains unread posts
Contains no unread posts
Contains no unread posts
More than 15 replies or 150 views
Hot thread with unread posts
More than 15 replies or 150 views
Hot thread with no unread posts
Closed Thread
Thread is closed
Thread Contains a Message Written By You
You have posted in this thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  

Top 84 Thread Starters For "Challenge Questions and Puzzles"

RankUser NamePercentage Of TotalThreadsMost Recent Thread
1anemone43.0747Show ⌊aš⁷⁸&#...
2Albert20.6358find a,b
3lfdahl7.1124Find the antiderivative
4kaliprasad3.561irrational number
5ZaidAlyafey2.239Harmonic numbers identity
6MarkFL1.831Definite Integral
7Random Variable1.628A residue calculation
8sbhatnagar1.526Two Challenging Integrals
9jacks1.425Indefinite integration involvi...
10DreamWeaver1.424An inverse tangential problem
11caffeinemachine0.915MHB's First Polymath Project.
12solakis0.814high school geometry
13Pranav0.713Summation challenge #2
14Krizalid0.610Continuity of IVP
14Wilmer0.610Tuff Sequence...
14checkittwice0.610Determine all solutions in pos...
15greg13130.59Trigonometric Sum
15magneto0.59Sequence Challenge
16mathmaniac0.586n^3 + 3 is not a perfect 6th ...
16eddybob1230.58Increasing and Decreasing Numb...
17melese0.47Rational roots
17I like Serena0.47Divide into 5 congruent pieces
17Rido120.47Find the limit (n!)^(1/n)/n
17hxthanh0.47Write n = a + b + c + ...
17mente oscura0.47Find the 6 reals roots
18CaptainBlack0.36Problem from Paper 3 of the 19...
18Bacterius0.36Divergence of a trigonometric ...
18soroban0.36The Missing intercept
18mathbalarka0.36A double sum challenge
18mathworker0.36pigeon hole proof
18Shobhit0.36An Infinite product
18Fallen Angel0.36Find all functions
19Poirot0.35Co-prime challenge
19sadsadsadsa0.35Ricky's Dinner
19jacobi0.35Probability challenge
20Evgeny.Makarov0.24Game on a chessboard
20jakncoke0.24Putnam 2012: A5
20Theia0.24Differentiation challenge
21Also sprach Zarathustra0.23Integral of x^{-x}
21alane19940.23Einstein's Riddle
21Farmtalk0.23Secret Order
21The Lord0.23Integral
21Petrus0.23Differential Equation challeng...
21castor280.23Weird function challenge
22chisigma0.12A false approach to an integra...
22TheBigBadBen0.12Logic problem
22M R0.12Geometry Challenge
22Fermat0.12integration
22Euge0.12Abstract Algebra Challenge
22Illmatic0.12Sum of reciprocals of roots
22jmprada0.12Sphere diameter
23The Chaz0.11Travelers and coins
23Prove It0.11Challenge: Is cos(pi/60) trans...
23Alexmahone0.11Hourglasses
23tkhunny0.11Missing in NY/PA
23Sherlock0.11Sum involving pi, ln(2) and Ca...
23Fernando Revilla0.11lim x ⌊1 / x⌋ , x...
23HallsofIvy0.11A geometric puzzle
23masters0.11Where's the father?
23DrunkenOldFool0.11infinite sum
23Opalg0.11Puzzle with digits
23Deveno0.11Identify the mystery group
23Amer0.11Nice Puzzle
23princeps0.11LCM Inequality
23Chris110.11Simple, fun puzzle
23QuestForInsight0.11Exponential limit
23topsquark0.11Sort of a challenge
23Petek0.11Unique Factorization Domains
23mssrki0.11Mathematics - a new basis
23johng0.11number of p subgroups
23judytl30.11Factoring over the Integers
23stainburg0.11Boring. Then Prove it!
23jeffer vitola0.11Limit is Sum
23individ0.11Solve triple square Diophantin...
23RLBrown0.11Next integer in this sequence,...
23Bibubo0.11divisibility and sums
23maxkor0.11exactly one triple
23Dai0.11Puzzle
23Prakhar0.11Challenging Integral
23RobJob0.11The connected Game
23Monoxdifly0.11Arrange Mathematical Operation...
23Joppy0.11Show that is the square of an ...
23bio0.11Year 7 & 8 mathematics puz...
23rick1230.11The Durango Curve Problem
Math Help Boards