This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A198227 #6 Feb 07 2025 16:44:05
%S A198227 6,2,6,4,6,6,3,3,7,8,4,9,2,9,1,8,6,3,0,1,2,3,5,0,1,0,6,3,3,5,8,7,6,2,
%T A198227 0,5,1,7,8,9,2,9,3,3,5,8,2,0,0,9,5,1,5,5,0,3,9,9,0,7,8,1,3,9,4,8,6,1,
%U A198227 4,5,9,9,3,6,8,6,8,3,4,8,4,1,9,0,9,8,8,5,9,7,9,7,7,0,7,2,3,1,7
%N A198227 Decimal expansion of least x having 3*x^2+2x=3*cos(x). Decimal expansion of greatest x having 3*x^2+2x=3*cos(x).
%C A198227 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198227 least x: -1.0904382560388744089252035126068065372...
%e A198227 greatest x: 0.626466337849291863012350106335876205...
%t A198227 a = 3; b = 2; c = 3;
%t A198227 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198227 Plot[{f[x], g[x]}, {x, -2, 1}]
%t A198227 r1 = x /. FindRoot[f[x] == g[x], {x, -1.1, -1.08}, WorkingPrecision -> 110]
%t A198227 RealDigits[r1] (* A198226 *)
%t A198227 r2 = x /. FindRoot[f[x] == g[x], {x, .62, .63}, WorkingPrecision -> 110]
%t A198227 RealDigits[r2] (* A198227 *)
%Y A198227 Cf. A197737.
%K A198227 nonn,cons
%O A198227 0,1
%A A198227 _Clark Kimberling_, Oct 23 2011