A019948 Decimal expansion of tangent of 50 degrees.

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

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn
• cons
• changed

Comments

Also the decimal expansion of cotangent of 40 degrees. - Ivan Panchenko, Sep 01 2014

Examples

			1.19175359259420995870530807186041933693070040770854385365483...
		

Links

• Ivan Panchenko, Table of n, a(n) for n = 1..1000
• Index entries for algebraic numbers, degree 6

Crossrefs

Cf. A019859 (sine of 50 degrees).

Programs

Magma

SetDefaultRealField(RealField(100)); R:= RealField(); Tan(5*Pi(R)/18); // G. C. Greubel, Nov 23 2018

Mathematica

RealDigits[Tan[5*Pi/18], 10, 100][[1]] (* G. C. Greubel, Nov 23 2018 *)

PARI

default(realprecision, 100); tan(5*Pi/18) \\ G. C. Greubel, Nov 23 2018

Sage

numerical_approx(tan(5*pi/18), digits=100) # G. C. Greubel, Nov 23 2018

Formula

A root of 3*x^6 -27*x^4 +33*x^2 -1 =0 (others A019968, A019908). - R. J. Mathar, Aug 29 2025