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A201521 Decimal expansion of least x satisfying 6*x^2 - 1 = sec(x) and 0 < x < Pi. 3

%I #9 Apr 10 2021 02:03:31

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

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

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

%N Decimal expansion of least x satisfying 6*x^2 - 1 = sec(x) and 0 < x < Pi.

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

%e least: 0.60805447799791305332799572251089761...

%e greatest: 1.489480656731833320399126017677317...

%t a = 6; c = -1;

%t f[x_] := a*x^2 + c; g[x_] := Sec[x]

%t Plot[{f[x], g[x]}, {x, 0, Pi/2}, {AxesOrigin -> {0, 0}}]

%t r = x /. FindRoot[f[x] == g[x], {x, .6, .7}, WorkingPrecision -> 110]

%t RealDigits[r] (* A201521 *)

%t r = x /. FindRoot[f[x] == g[x], {x, 1.4, 1.5}, WorkingPrecision -> 110]

%t RealDigits[r] (* A201522 *)

%Y Cf. A201397.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Dec 02 2011

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Last modified July 24 15:18 EDT 2024. Contains 374584 sequences. (Running on oeis4.)