login

Reminder: The OEIS is hiring a new managing editor, and the application deadline is January 26.

Decimal expansion of x>0 satisfying 3*x^2-4*cos(x)=1.
2

%I #5 Mar 30 2012 18:57:56

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

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

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

%N Decimal expansion of x>0 satisfying 3*x^2-4*cos(x)=1.

%C See A198755 for a guide to related sequences. The Mathematica program includes a graph.

%e x=1.017085503374383130722072016771626089566461...

%t a = 3; b = -4; c = 1;

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

%t Plot[{f[x], g[x]}, {x, -2, 2}, {AxesOrigin -> {0, 0}}]

%t r = x /. FindRoot[f[x] == g[x], {x, 1.01, 1.02}, WorkingPrecision -> 110]

%t RealDigits[r] (* A198939 *)

%Y Cf. A198755.

%K nonn,cons

%O 1,4

%A _Clark Kimberling_, Nov 01 2011