A200106 Decimal expansion of greatest x satisfying x^2 - 4*cos(x) = 4*sin(x).

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

Offset

1,2

Comments

See A199949 for a guide to related sequences. The Mathematica program includes a graph.

Links

G. C. Greubel, Table of n, a(n) for n = 1..10000

Example

least x: -0.698933604732903309337989544733567956233...
greatest x: 1.7695688743727017491150784620016277547...

Mathematica

a = 1; b = -4; c = 4;
f[x_] := a*x^2 + b*Cos[x]; g[x_] := c*Sin[x]
Plot[{f[x], g[x]}, {x, -3, 3}, {AxesOrigin -> {0, 0}}]
r = x /. FindRoot[f[x] == g[x], {x, -.7, -.6}, WorkingPrecision -> 110]
RealDigits[r]  (* A200105 *)
r = x /. FindRoot[f[x] == g[x], {x, 1.76, 1.77}, WorkingPrecision -> 110]
RealDigits[r]  (* A200106 *)

Prog

(PARI) a=1; b=-4; c=4; solve(x=1, 2, a*x^2 + b*cos(x) - c*sin(x)) \\ G. C. Greubel, Jun 25 2018

Crossrefs

Cf. A199949.

Sequence in context: A273066 A257964 A178816 * A201766 A307951 A197588

Adjacent sequences: A200103 A200104 A200105 * A200107 A200108 A200109

Keyword

nonn,cons

Author

Clark Kimberling, Nov 13 2011

Status

approved