A201669 Decimal expansion of greatest x satisfying 4*x^2 - 1 = csc(x) and 0<x<Pi.

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

Offset

1,1

Comments

See A201564 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:  0.7784767772775942312900352799867268779861...
greatest:  3.1151461160403612671519315474503258920...

Mathematica

a = 4; c = -1;
f[x_] := a*x^2 + c; g[x_] := Csc[x]
Plot[{f[x], g[x]}, {x, 0, Pi}, {AxesOrigin -> {0, 0}}]
r = x /. FindRoot[f[x] == g[x], {x, .7, .8}, WorkingPrecision -> 110]
RealDigits[r]     (* A201668 *)
r = x /. FindRoot[f[x] == g[x], {x, 3.0, 3.14}, WorkingPrecision -> 110]
RealDigits[r]     (* A201669 *)

Prog

(PARI) a=4; c=-1; solve(x=3, 3.14, a*x^2 + c - 1/sin(x)) \\ G. C. Greubel, Sep 11 2018

Crossrefs

Cf. A201564.

Sequence in context: A261698 A124738 A131086 * A069002 A245369 A076334

Adjacent sequences: A201666 A201667 A201668 * A201670 A201671 A201672

Keyword

nonn,cons

Author

Clark Kimberling, Dec 04 2011

Status

approved