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%I #8 Apr 10 2021 20:56:53
%S 5,2,2,9,4,1,8,3,0,5,6,4,4,4,6,6,3,1,5,9,1,8,6,1,8,5,6,1,6,3,9,6,6,8,
%T 9,0,9,4,0,6,9,3,6,3,6,5,8,7,5,9,3,0,4,1,0,8,6,5,6,6,1,9,9,0,2,3,3,3,
%U 5,3,0,5,8,9,4,2,9,7,8,5,6,3,9,7,8,7,6,1,9,0,7,2,8,6,4,5,3,4,1
%N Decimal expansion of x satisfying 10*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=0.522941830564446631591861856163966890940693...
%t a = 10; 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, .5, .6}, WorkingPrecision -> 110]
%t RealDigits[r] (* A201328 *)
%Y Cf. A201280.
%K nonn,cons
%O 0,1
%A _Clark Kimberling_, Nov 30 2011