A201423 Decimal expansion of greatest x satisfying 10*x^2 = sec(x) and 0 < x < Pi.

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

Offset

1,2

Comments

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

Links

Table of n, a(n) for n=1..100.

Example

least:  0.3248357625526726343272168905918357...
greatest: 1.52794989469861441964924475246801...

Mathematica

a = 10; c = 0;
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, .3, .4}, WorkingPrecision -> 110]
RealDigits[r]    (* A201422 *)
r = x /. FindRoot[f[x] == g[x], {x, 1.5, 1.6}, WorkingPrecision -> 110]
RealDigits[r]    (* A201423 *)

Crossrefs

Cf. A201397.

Sequence in context: A074454 A256110 A267211 * A155790 A200646 A198130

Adjacent sequences: A201420 A201421 A201422 * A201424 A201425 A201426

Keyword

nonn,cons

Author

Clark Kimberling, Dec 02 2011

Status

approved