A019987 Decimal expansion of tangent of 89 degrees.
5, 7, 2, 8, 9, 9, 6, 1, 6, 3, 0, 7, 5, 9, 4, 2, 4, 6, 8, 7, 2, 7, 8, 1, 4, 7, 5, 3, 7, 1, 1, 2, 5, 7, 7, 9, 8, 0, 2, 1, 7, 5, 2, 2, 2, 3, 5, 1, 4, 3, 9, 2, 6, 4, 7, 2, 5, 8, 1, 1, 0, 3, 6, 0, 6, 5, 2, 9, 2, 2, 8, 9, 3, 6, 4, 7, 9, 1, 9, 3, 0, 6, 7, 2, 4, 1, 6, 2, 8, 2, 2, 0, 6, 8, 3, 8, 8, 0, 6
Offset: 2
Examples
57.28996...
Links
- Ivan Panchenko, Table of n, a(n) for n = 2..1000.
- Art of Problem Solving, USAMO 1996, Problem 1.
- Mohammad K. Azarian, Forty-Five Nested Equilateral Triangles and cosecant of 1 degree, Problem 813, College Mathematics Journal, Vol. 36, No. 5, November 2005, p. 413-414; Solution, College Mathematics Journal, Vol. 37, No. 5, November 2006, pp. 394-395.
- User ssaamil, I found a cool number I'd like to share, 57289961630759424687278147537112577980217. In reddit.com/r/math, May 12 2023
- Index to sequences related to Olympiads.
- Index entries for algebraic numbers, degree 24
Programs
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Maple
evalf(cot(Pi/180),100); # Bernard Schott, Apr 30 2022
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Mathematica
First[RealDigits[Cot[Pi/180], 10, 100]] (* Paolo Xausa, Apr 23 2024 *)
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PARI
tan(89*Pi/180) \\ Charles R Greathouse IV, Aug 27 2017
Formula
Equals (Sum_{k=1..90} 2*k*sin(2*k)) / 90, with k in degrees (link USAMO 1996). - Bernard Schott, Apr 30 2022
A largest of the 24 real-valued roots of 1 -48*x +x^24 -564*x^22 +21186*x^20 -269412*x^18 +1470447*x^16 -3923304*x^14 +5407388*x^12 -3923304*x^10 +1470447*x^8- 269412*x^6 +21186*x^4 -564*x^2 -48*x^23 +1456*x^21 -12432*x^19 +17424*x^17 +45344*x^15 -51744*x^13 -51744*x^11 +45344*x^9 +17424*x^7 -12432*x^5 +1456*x^3 =0.- R. J. Mathar, Aug 29 2025
Extensions
Edited by N. J. A. Sloane, Aug 19 2008 at the suggestion of R. J. Mathar
Comments