A201321 - OEIS

%I #8 Apr 10 2021 20:58:37

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

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

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

%N Decimal expansion of x satisfying 3*x^2 - 1 = cot(x) and 0 < x < Pi.

%C See A201280 for a guide to related sequences. The Mathematica program includes a graph.

%e x=0.807585281442201993926581679537240754...

%t a = 3; c = -1;

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

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

%t r = x /. FindRoot[f[x] == g[x], {x, .8, .9}, WorkingPrecision -> 110]

%t RealDigits[r]    (* A201321 *)

%Y Cf. A201280.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Nov 30 2011