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

%I #6 Feb 07 2025 16:44:05

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

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

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

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

%C See A198414 for a guide to related sequences. The Mathematica program includes a graph.

%e x=-1.2357835607579307244452120871021674772...

%t a = 1; b = 2; c = 1;

%t f[x_] := a*x^2 + b*x; g[x_] := c*Sin[x]

%t Plot[{f[x], g[x]}, {x, -2, 1}]

%t r = x /. FindRoot[f[x] == g[x], {x, -1.3, -1.2}, WorkingPrecision -> 110]

%t RealDigits[r] (* A198424 *)

%Y Cf. A198414.

%K nonn,cons

%O 1,2

%A _Clark Kimberling_, Oct 25 2011