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 A198241 #6 Feb 07 2025 16:44:05
%S A198241 4,8,6,0,0,4,4,3,5,9,9,2,2,9,3,0,4,0,8,1,6,1,9,8,9,8,1,5,0,3,5,7,8,5,
%T A198241 6,4,6,9,2,1,1,0,8,7,9,7,3,0,9,4,7,7,4,2,5,5,3,7,9,8,3,9,2,2,9,1,8,0,
%U A198241 2,6,8,1,9,8,3,7,6,9,9,0,9,0,6,2,7,7,5,3,7,1,6,2,9,0,0,4,5,7,7
%N A198241 Decimal expansion of greatest x having 3*x^2+4x=3*cos(x).
%C A198241 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198241 least x: -1.4308334207177285425665439336391388599...
%e A198241 greatest x: 0.48600443599229304081619898150357856...
%t A198241 a = 3; b = 4; c = 3;
%t A198241 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198241 Plot[{f[x], g[x]}, {x, -2, 1}]
%t A198241 r1 = x /. FindRoot[f[x] == g[x], {x, -1.5, -1.4}, WorkingPrecision -> 110]
%t A198241 RealDigits[r1](* A198240 *)
%t A198241 r2 = x /. FindRoot[f[x] == g[x], {x, .48, .49}, WorkingPrecision -> 110]
%t A198241 RealDigits[r2] (* A198241 *)
%Y A198241 Cf. A197737.
%K A198241 nonn,cons
%O A198241 0,1
%A A198241 _Clark Kimberling_, Oct 23 2011