A199176 Decimal expansion of x<0 satisfying x^2+2*x*cos(x)=1.
1, 3, 0, 1, 2, 0, 1, 7, 3, 3, 1, 4, 1, 9, 1, 1, 4, 0, 0, 7, 9, 8, 3, 9, 7, 3, 6, 4, 4, 4, 0, 2, 6, 4, 5, 2, 2, 1, 9, 1, 3, 0, 0, 6, 5, 7, 4, 3, 0, 3, 0, 4, 8, 9, 2, 6, 9, 4, 6, 0, 5, 7, 9, 4, 6, 6, 0, 3, 7, 1, 9, 0, 5, 4, 5, 5, 9, 6, 8, 1, 3, 3, 2, 4, 3, 2, 9, 6, 9, 4, 8, 2, 3, 0, 7, 2, 9, 2, 9
Offset: 1
Examples
negative: -1.301201733141911400798397364440264522... positive: 0.444416809391791633213083601823107078...
Crossrefs
Cf. A199170.
Programs
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Mathematica
a = 1; b = 2; c = 1; f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c Plot[{f[x], g[x]}, {x, -2 Pi, 2 Pi}, {AxesOrigin -> {0, 0}}] r = x /. FindRoot[f[x] == g[x], {x, -1.4, -1.3}, WorkingPrecision -> 110] RealDigits[r] (* A199176 *) r = x /. FindRoot[f[x] == g[x], {x, .44, .45}, WorkingPrecision -> 110] RealDigits[r] (* A199177 *)
Comments