A198213 - OEIS

%I #5 Mar 30 2012 18:57:54

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

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

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

%N Decimal expansion of x>0 having 3*x^2=4*cos(x).

%C See A197737 for a guide to related sequences.  The Mathematica program includes a graph.

%e x=0.90659247409243796697930682467214938...

%t a = 3; b = 0; c = 4;

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

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

%t r = x /. FindRoot[f[x] == g[x], {x, 0.90, 0.91}, WorkingPrecision -> 110]

%t RealDigits[r] (* A198213 *)

%Y Cf. A197737.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Oct 22 2011