A198987 Decimal expansion of x>0 satisfying 4*x^2-cos(x)=1.
6, 6, 8, 0, 2, 7, 8, 4, 7, 4, 5, 3, 0, 5, 4, 0, 7, 4, 5, 0, 2, 2, 2, 0, 0, 5, 6, 3, 7, 3, 9, 8, 6, 8, 5, 1, 2, 1, 5, 7, 9, 0, 2, 6, 8, 8, 8, 4, 0, 9, 1, 8, 5, 4, 6, 5, 4, 3, 7, 6, 9, 1, 1, 6, 4, 6, 9, 0, 9, 7, 0, 4, 3, 4, 0, 1, 0, 5, 4, 1, 5, 5, 4, 1, 4, 6, 8, 1, 7, 2, 3, 5, 5, 4, 3, 3, 0, 9, 4
Offset: 0
Examples
0.668027847453054074502220056373986851215790...
Crossrefs
Cf. A198755.
Programs
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Mathematica
a = 4; b = -1; c = 1; f[x_] := a*x^2 + b*Cos[x]; g[x_] := c Plot[{f[x], g[x]}, {x, -2, 2}, {AxesOrigin -> {0, 0}}] r = x /. FindRoot[f[x] == g[x], {x, .66, .67}, WorkingPrecision -> 110] RealDigits[r] (* A198987 *)
Comments