A201419 Decimal expansion of greatest x satisfying 8*x^2 = sec(x) and 0 < x < Pi.
1, 5, 1, 6, 4, 0, 9, 8, 4, 8, 1, 1, 1, 9, 3, 5, 5, 8, 9, 6, 3, 6, 2, 1, 8, 9, 4, 0, 7, 7, 5, 1, 9, 7, 0, 8, 0, 7, 6, 6, 7, 9, 5, 6, 1, 1, 8, 2, 4, 4, 3, 0, 6, 3, 4, 7, 6, 0, 8, 6, 1, 0, 3, 9, 9, 9, 5, 2, 4, 0, 4, 5, 1, 7, 0, 0, 0, 1, 2, 8, 9, 8, 1, 1, 2, 1, 9, 0, 3, 9, 7, 8, 2, 8, 9, 3, 9, 6, 8
Offset: 1
Examples
least: 0.365868442181046909444887950918036646081... greatest: 1.5164098481119355896362189407751970807...
Crossrefs
Cf. A201397.
Programs
-
Mathematica
a = 8; 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] (* A201418 *) r = x /. FindRoot[f[x] == g[x], {x, 1.5, 1.6}, WorkingPrecision -> 110] RealDigits[r] (* A201419 *)
Comments