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A019859
Decimal expansion of sine of 50 degrees.
6
7, 6, 6, 0, 4, 4, 4, 4, 3, 1, 1, 8, 9, 7, 8, 0, 3, 5, 2, 0, 2, 3, 9, 2, 6, 5, 0, 5, 5, 5, 4, 1, 6, 6, 7, 3, 9, 3, 5, 8, 3, 2, 4, 5, 7, 0, 8, 0, 3, 9, 5, 2, 4, 5, 8, 5, 4, 0, 4, 5, 2, 8, 4, 6, 4, 2, 1, 5, 5, 3, 8, 8, 8, 5, 6, 8, 7, 4, 7, 2, 3, 5, 2, 8, 2, 2, 9, 2, 7, 6, 6, 8, 0, 5, 4, 8, 4, 9, 3
OFFSET
0,1
COMMENTS
A cubic number with denominator 2 and minimal polynomial 8x^3 - 6x + 1. - Charles R Greathouse IV, Nov 05 2017
The roots of the polynomial 8x^3 - 6x + 1 can be constructed using the intersection of the circle defined by x^(2) + y^(2) - 0.125x + 0.25y = 0.75 and the hyperbola defined by -8xy+y=-1. The circle and the hyperbola intersect at (0,-1) and 3 other points. 3 lines can be drawn by connecting the point (0,-1) to the other 3 points of intersection. The 3 lines intersect the x-axis at the locations of the roots. - Raul Prisacariu, Jul 29 2024
FORMULA
Equals cos(2*Pi/9) = 2F1(5/6,1/6;1/2;3/4) / 2. - R. J. Mathar, Oct 27 2008
Equals 2*A019834*A019874. - R. J. Mathar, Jan 17 2021
EXAMPLE
0.76604444...
MATHEMATICA
RealDigits[ Cos[ 2Pi/9], 10, 111][[1]] (* Robert G. Wilson v *)
RealDigits[Sin[50 Degree], 10, 120][[1]] (* Harvey P. Dale, Dec 19 2012 *)
PROG
(PARI) sin(5/18*Pi) \\ Charles R Greathouse IV, Nov 05 2017
CROSSREFS
Sequence in context: A371322 A198109 A059751 * A188736 A265304 A102769
KEYWORD
nonn,cons
STATUS
approved