A199619 Decimal expansion of least x>0 satisfying x^2+4*x*cos(x)=4*sin(x).
8, 0, 0, 0, 5, 3, 3, 4, 2, 6, 2, 7, 4, 1, 5, 7, 5, 9, 3, 6, 8, 5, 9, 0, 2, 7, 9, 9, 0, 8, 9, 3, 3, 2, 1, 9, 6, 3, 2, 4, 4, 6, 5, 3, 4, 4, 8, 6, 4, 6, 6, 6, 1, 1, 0, 4, 6, 2, 1, 6, 6, 9, 1, 9, 5, 3, 4, 1, 3, 1, 1, 0, 2, 7, 7, 5, 0, 4, 3, 4, 1, 5, 9, 6, 8, 4, 1, 0, 1, 2, 2, 2, 9, 0, 1, 5, 2, 7, 6
Offset: 0
Examples
least: 0.80005334262741575936859027990893321963... greatest: 3.4528998885329277803363008378649838...
Crossrefs
Cf. A199597.
Programs
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Mathematica
a = 1; b = 4; c = 4; f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x] Plot[{f[x], g[x]}, {x, -.5, 4}, {AxesOrigin -> {0, 0}}] r = x /. FindRoot[f[x] == g[x], {x, .8, .81}, WorkingPrecision -> 110] RealDigits[r] (* A199619, least pos root *) r = x /. FindRoot[f[x] == g[x], {x, 3.4, 3.5}, WorkingPrecision -> 110] RealDigits[r] (* A199620, greatest of 3 roots *)
Comments