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%I #5 Mar 30 2012 18:57:53
%S 7,7,3,6,9,6,1,8,9,2,4,3,8,0,9,4,2,1,7,1,4,7,3,9,0,5,3,5,3,0,4,5,3,3,
%T 3,6,8,0,5,7,2,1,2,5,6,8,2,4,5,8,2,4,0,7,9,1,1,0,4,5,4,2,4,9,8,1,2,9,
%U 4,1,0,7,6,2,5,1,4,0,0,5,2,7,0,1,6,9,0,0,6,3,8,8,0,4,0,8,2,8,2
%N Decimal expansion of greatest x having x^2+2x=3*cos(x).
%C See A197737 for a guide to related sequences. The Mathematica program includes a graph.
%e least x: -1.72807808625314217139724543242476826...
%e greatest x: 0.773696189243809421714739053530453...
%t a = 1; b = 2; c = 3;
%t f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
%t Plot[{f[x], g[x]}, {x, -2, 1}]
%t r1 = x /. FindRoot[f[x] == g[x], {x, -1.8, -1.7}, WorkingPrecision -> 110]
%t RealDigits[r1] (* A197845 *)
%t r2 = x /. FindRoot[f[x] == g[x], {x, .77, .78}, WorkingPrecision -> 110]
%t RealDigits[r2] (* A197846 *)
%Y Cf. A197737.
%K nonn,cons
%O 0,1
%A _Clark Kimberling_, Oct 20 2011