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

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

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

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

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

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

%C See A199170 for a guide to related sequences. The Mathematica program includes a graph.

%e negative: -1.0835116610219289883304749103821255...

%e positive: 0.48645750461686637457544128449375285...

%t a = 3; b = 3; c = 2;

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

%t Plot[{f[x], g[x]}, {x, -3, 3}, {AxesOrigin -> {0, 0}}]

%t r = x /. FindRoot[f[x] == g[x], {x, -1, -.9}, WorkingPrecision -> 110]

%t RealDigits[r] (* A199293 *)

%t r = x /. FindRoot[f[x] == g[x], {x, .48, .49}, WorkingPrecision -> 110]

%t RealDigits[r] (* A199294 *)

%Y Cf. A199170.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Nov 05 2011