A201568 Decimal expansion of least x satisfying x^2 + 4 = csc(x) and 0 < x < Pi.

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

Offset

0,1

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 = 0..10000

Example

least:  0.2487490007162959853652924083716941039...
greatest:  3.0669301776557967159210627137381980...

Mathematica

a = 1; c = 4;
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, .2, .3}, WorkingPrecision -> 110]
RealDigits[r]   (* A201568 *)
r = x /. FindRoot[f[x] == g[x], {x, 3.0, 3.1}, WorkingPrecision -> 110]
RealDigits[r]   (* A201569 *)

Prog

(PARI) a=1; c=4; solve(x=0.2, .3, a*x^2 + c - 1/sin(x)) \\ G. C. Greubel, Aug 21 2018

Crossrefs

Cf. A201564.

Sequence in context: A061284 A016017 A071571 * A029898 A153130 A225746

Adjacent sequences: A201565 A201566 A201567 * A201569 A201570 A201571

Keyword

nonn,cons

Author

Clark Kimberling, Dec 03 2011

Status

approved