A201327 - OEIS

%I #10 Jan 30 2025 16:02:38

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

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

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

%N Decimal expansion of x satisfying 9*x^2 - 1 = cot(x) and 0 < x < Pi.

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

%H <a href="/index/Tra#transcendental">Index entries for transcendental numbers</a>.

%e 0.543245472511065637161807400724287350...

%t a = 9; 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]   (* A201327 *)

%Y Cf. A201280.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Nov 30 2011