login
A201515
Decimal expansion of least x satisfying 3*x^2 - 1 = sec(x) and 0 < x < Pi.
3
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.
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
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Dec 02 2011
STATUS
approved