A195708 Decimal expansion of arccos(sqrt(2/5)) and of arcsin(sqrt(3/5)).

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

Offset: 0

Author

Clark Kimberling, Sep 23 2011

Keywords

• nonn
• cons

Examples

			0.886077123792...
		

Links

• G. C. Greubel, Table of n, a(n) for n = 0..5000
• Index entries for transcendental numbers

Crossrefs

Cf. A073000, A105199, A195701.

Programs

Magma

[Arccos(Sqrt(2/5))]; // G. C. Greubel, Nov 18 2017

Mathematica

r = Sqrt[1/5]; s = Sqrt[2/5];
N[ArcSin[r], 100]
RealDigits[%]  (* A073000 *)
N[ArcCos[r], 100]
RealDigits[%]  (* A105199 *)
N[ArcTan[r], 100]
RealDigits[%]  (* A188595 *)
N[ArcCos[-r], 100]
RealDigits[%]  (* A137218 *)
N[ArcSin[s], 100]
RealDigits[%]  (* A195701 *)
N[ArcCos[s], 100]
RealDigits[%]  (* A195708 *)
N[ArcTan[s], 100]
RealDigits[%]  (* A195709 *)
N[ArcCos[-s], 100]
RealDigits[%]  (* A195710 *)

PARI

acos(sqrt(2/5)) \\ G. C. Greubel, Nov 18 2017

Formula

Equals arctan(sqrt(3/2)). - Amiram Eldar, Jul 04 2023