login
Decimal expansion of x>0 satisfying 2*x^2+x*cos(x)=4*sin(x).
2

%I #5 Mar 30 2012 18:57:58

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

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

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

%N Decimal expansion of x>0 satisfying 2*x^2+x*cos(x)=4*sin(x).

%C See A199597 for a guide to related sequences. The Mathematica program includes a graph.

%e x=1.33887388985548526406255415475435291...

%t a = 2; b = 1; c = 4;

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

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

%t r = x /. FindRoot[f[x] == g[x], {x, 1.3, 1.4}, WorkingPrecision -> 110]

%t RealDigits[r] (* A199624 *)

%Y Cf. A199597.

%K nonn,cons

%O 1,2

%A _Clark Kimberling_, Nov 08 2011