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

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

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

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

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

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

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

%e negative: -0.923207967022272918085370562946372...

%e positive: 0.6988053514945826378907251192096740...

%t a = 3; b = 1; c = 2;

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

%t Plot[{f[x], g[x]}, {x, -1, 1}, {AxesOrigin -> {0, 0}}]

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

%t RealDigits[r] (* A199281 *)

%t r = x /. FindRoot[f[x] == g[x], {x, .69, .70}, WorkingPrecision -> 110]

%t RealDigits[r] (* A199282 *)

%Y Cf. A199170.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Nov 05 2011