A201409 Decimal expansion of greatest x satisfying 3*x^2 = sec(x) and 0 < x < Pi.
1, 3, 9, 9, 8, 6, 4, 1, 1, 9, 4, 4, 6, 0, 6, 4, 0, 6, 7, 2, 2, 9, 6, 3, 9, 5, 0, 5, 1, 8, 3, 6, 1, 0, 3, 7, 3, 9, 4, 1, 7, 8, 5, 0, 3, 3, 6, 2, 5, 3, 2, 6, 3, 4, 4, 2, 0, 4, 1, 4, 9, 8, 8, 7, 0, 4, 9, 5, 8, 0, 2, 7, 1, 7, 3, 5, 1, 0, 6, 0, 0, 3, 3, 5, 7, 9, 7, 0, 2, 0, 5, 7, 8, 1, 6, 5, 9, 1, 9
Offset: 1
Examples
least: 0.6461374540628972972901679159101125226952859... greatest: 1.39986411944606406722963950518361037394178...
Crossrefs
Cf. A201397.
Programs
-
Mathematica
a = 3; 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, .6, .7}, WorkingPrecision -> 110] RealDigits[r] (* A201408 *) r = x /. FindRoot[f[x] == g[x], {x, 1.3, 1.4}, WorkingPrecision -> 110] RealDigits[r] (* A201409 *)
Comments