A201569 Decimal expansion of greatest x satisfying x^2 + 4 = csc(x) and 0 < x < Pi.

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

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:  0.2487490007162959853652924083716941039...
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=3, 3.1, a*x^2 + c - 1/sin(x)) \\ G. C. Greubel, Aug 21 2018

Crossrefs

Cf. A201564.

Sequence in context: A004606 A019808 A182145 * A056459 A021330 A199055

Adjacent sequences: A201566 A201567 A201568 * A201570 A201571 A201572

Keyword

nonn,cons

Author

Clark Kimberling, Dec 03 2011

Status

approved