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Decimal expansion of x>0 having x^2+x=cos(x).
3

%I #6 Mar 30 2012 18:57:53

%S 5,5,0,0,0,9,3,4,9,9,2,7,2,6,1,5,6,6,6,6,4,9,5,3,6,1,9,4,7,1,7,2,9,2,

%T 6,1,1,6,7,2,8,5,0,9,2,4,3,5,7,9,3,7,8,4,5,7,0,9,3,9,2,2,0,4,2,5,2,6,

%U 0,4,4,5,2,5,2,4,4,5,3,3,2,8,5,3,9,2,4,4,5,4,3,1,6,4,9,6,4,4,7

%N Decimal expansion of x>0 having x^2+x=cos(x).

%C For a discussion and guide to related sequences, see A197737.

%e negative: -1.25115183522076481159287006878816185994...

%e positive: 0.55000934992726156666495361947172926116...

%t a = 1; b = 1; c = 1;

%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, -1.26, -1.25}, WorkingPrecision -> 110]

%t RealDigits[r1] (* A197737 *)

%t r1 = x /. FindRoot[f[x] == g[x], {x, .55, .551}, WorkingPrecision -> 110]

%t RealDigits[r1] (* A197738 *)

%Y Cf. A197737.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Oct 20 2011