A201515 Decimal expansion of least x satisfying 3*x^2 - 1 = sec(x) and 0 < x < Pi.

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

Offset

0,1

Comments

See A201397 for a guide to related sequences. The Mathematica program includes a graph.

Links

Table of n, a(n) for n=0..98.

Example

least:  0.95353909754991468966727069537237822743...
greatest: 1.341430166291259764576080506763614171...

Mathematica

a = 3; c = -1;
f[x_] := a*x^2 + c; g[x_] := Sec[x]
Plot[{f[x], g[x]}, {x, 0, Pi/2}, {AxesOrigin -> {0, 0}}]
r = x /. FindRoot[f[x] == g[x], {x, .9, 1}, WorkingPrecision -> 110]
RealDigits[r]  (* A201515 *)
r = x /. FindRoot[f[x] == g[x], {x, 1.3, 1.5}, WorkingPrecision -> 110]
RealDigits[r]  (* A201516 *)

Crossrefs

Cf. A201397.

Sequence in context: A158270 A154543 A203132 * A343619 A259982 A200483

Adjacent sequences: A201512 A201513 A201514 * A201516 A201517 A201518

Keyword

nonn,cons

Author

Clark Kimberling, Dec 02 2011

Status

approved