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%I #5 Mar 30 2012 18:57:53
%S 2,3,8,8,9,4,9,3,4,3,6,0,8,9,0,4,5,9,6,8,7,0,4,3,2,6,7,8,1,9,7,3,0,9,
%T 9,2,9,6,6,3,3,0,6,0,2,9,4,6,2,2,9,0,1,9,9,1,1,6,9,1,8,0,1,5,0,7,5,0,
%U 6,1,3,9,6,6,1,9,5,3,1,0,8,6,7,7,8,1,1,0,6,0,0,3,7,0,5,5,5,8,6
%N Decimal expansion of least x having x^2+3x=2*cos(x).
%C See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e least x: -2.38894934360890459687043267819730...
%e greatest x: 0.5010411864464903833151417790663...
%t a = 1; b = 3; c = 2;
%t f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t Plot[{f[x], g[x]}, {x, -3, 1}]
%t r1 = x /. FindRoot[f[x] == g[x], {x, -2.4, -2.3}, WorkingPrecision -> 110]
%t RealDigits[r1] (* A198104 *)
%t r2 = x /. FindRoot[f[x] == g[x], {x, .5, .51}, WorkingPrecision -> 110]
%t RealDigits[r2] (* A198105 *)
%Y Cf. A197737.
%K nonn,cons
%O 1,1
%A _Clark Kimberling_, Oct 21 2011