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 A198222 #8 Feb 07 2025 16:44:05
%S A198222 8,9,7,9,9,1,2,1,7,8,1,5,7,7,3,7,2,3,2,7,0,9,4,3,4,7,4,5,5,1,2,3,8,3,
%T A198222 2,2,3,4,4,2,6,5,1,2,3,7,9,3,4,8,0,7,1,3,1,4,1,5,1,3,4,7,0,8,1,2,5,4,
%U A198222 3,5,5,9,8,9,3,2,4,5,5,8,5,1,9,4,4,4,4,2,6,7,2,5,8,4,4,1,4,4,5,7
%N A198222 Decimal expansion of least x having 3*x^2+2x=cos(x).
%C A198222 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198222 least x: -0.8979912178157737232709434745512383...
%e A198222 greatest x: 0.320480477969135711421623476182676393...
%t A198222 a = 3; b = 2; c = 1;
%t A198222 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198222 Plot[{f[x], g[x]}, {x, -1, 1}]
%t A198222 r1 = x /. FindRoot[f[x] == g[x], {x, -.9, -.8}, WorkingPrecision -> 110]
%t A198222 RealDigits[r1] (* A198222 *)
%t A198222 r2 = x /. FindRoot[f[x] == g[x], {x, .3, .4}, WorkingPrecision -> 110]
%t A198222 RealDigits[r2] (* A198223 *)
%Y A198222 Cf. A197737.
%K A198222 nonn,cons
%O A198222 0,1
%A A198222 _Clark Kimberling_, Oct 22 2011