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 A198372 #6 Feb 07 2025 16:44:05
%S A198372 4,6,0,1,9,4,9,9,7,7,5,0,9,3,0,9,7,1,4,2,4,7,9,7,2,7,7,9,6,4,5,5,8,8,
%T A198372 6,1,6,5,4,5,0,0,5,1,8,5,7,4,4,9,2,0,1,8,4,8,3,1,1,1,0,4,0,7,7,7,4,6,
%U A198372 4,8,7,8,7,8,6,5,8,1,6,3,2,7,1,7,8,9,2,8,3,6,1,8,1,4,4,0,5,9,8
%N A198372 Decimal expansion of greatest x having 4*x^2+4x=3*cos(x).
%C A198372 See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e A198372 least x: -1.21501298426435245704887128499150254...
%e A198372 greatest x: 0.460194997750930971424797277964558861...
%t A198372 a = 4; b = 4; c = 3;
%t A198372 f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t A198372 Plot[{f[x], g[x]}, {x, -2, 1}]
%t A198372 r1 = x /. FindRoot[f[x] == g[x], {x, -1.3, -1.2}, WorkingPrecision -> 110]
%t A198372 RealDigits[r1] (* A198371 *)
%t A198372 r2 = x /. FindRoot[f[x] == g[x], {x, .46, .47}, WorkingPrecision -> 110]
%t A198372 RealDigits[r2] (* A198372 *)
%Y A198372 Cf. A197737.
%K A198372 nonn,cons
%O A198372 0,1
%A A198372 _Clark Kimberling_, Oct 24 2011