A019893 Decimal expansion of sine of 84 degrees.

9, 9, 4, 5, 2, 1, 8, 9, 5, 3, 6, 8, 2, 7, 3, 3, 3, 6, 9, 2, 2, 6, 9, 1, 9, 4, 4, 9, 8, 0, 5, 7, 0, 3, 8, 1, 5, 2, 0, 7, 9, 2, 0, 8, 8, 7, 0, 9, 3, 1, 9, 4, 2, 7, 3, 6, 6, 5, 5, 8, 8, 3, 3, 5, 7, 4, 3, 1, 6, 2, 5, 0, 6, 8, 6, 8, 9, 8, 3, 6, 2, 5, 7, 9, 3, 0, 6, 2, 2, 0, 3, 8, 3, 3, 6, 0, 9, 2, 9

Offset

0,1

Comments

Equals sin(7*Pi/15). - Wesley Ivan Hurt, Sep 01 2014

An algebraic number of degree 8 and denominator 2. - Charles R Greathouse IV, Aug 27 2017

Links

Ivan Panchenko, Table of n, a(n) for n = 0..1000

Wikipedia, Exact trigonometric constants

Index entries for algebraic numbers, degree 8

Formula

Equals cos(Pi/30) = 2F1(11/20,9/20;1/2;3/4) / 2. - R. J. Mathar, Oct 27 2008

Equals 2*A019851*A019857. - R. J. Mathar, Jan 17 2021

Example

0.9945218953682733369226919449805703815207920887093194273665588...

Maple

Digits:=100: evalf(sin(7*Pi/15)); # Wesley Ivan Hurt, Sep 01 2014

Mathematica

RealDigits[ Cos[Pi/30], 10, 111] (* Robert G. Wilson v *)
RealDigits[Sin[84 Degree], 10, 120][[1]] (* Harvey P. Dale, May 14 2022 *)

Prog

(PARI) cos(Pi/30) \\ Charles R Greathouse IV, Aug 27 2017

Crossrefs

Sequence in context: A283749 A249023 A336044 * A346585 A117023 A013668

Adjacent sequences: A019890 A019891 A019892 * A019894 A019895 A019896

Keyword

nonn,cons

Author

N. J. A. Sloane.

Status

approved