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
Examples
least: 0.95353909754991468966727069537237822743... greatest: 1.341430166291259764576080506763614171...
Crossrefs
Cf. A201397.
Programs
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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 *)
Comments