A199742 Decimal expansion of x>0 satisfying 2*x^2-x*cos(x)=sin(x).
7, 9, 7, 7, 7, 5, 5, 9, 3, 3, 0, 1, 3, 9, 6, 5, 6, 4, 7, 3, 4, 0, 8, 3, 2, 2, 9, 1, 2, 9, 0, 2, 4, 5, 4, 4, 4, 1, 8, 4, 2, 8, 9, 4, 1, 3, 6, 1, 8, 0, 6, 2, 5, 8, 3, 6, 2, 8, 4, 6, 0, 1, 5, 1, 1, 2, 9, 9, 9, 1, 1, 6, 8, 4, 5, 4, 0, 3, 8, 6, 7, 5, 8, 8, 2, 3, 3, 0, 3, 1, 6, 3, 1, 5, 3, 5, 0, 3, 1
Offset: 0
Examples
0.797775593301396564734083229129024544418428941...
Crossrefs
Cf. A199597.
Programs
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Mathematica
a = 2; b = -1; c = 1; f[x_] := a*x^2 + b*x*Cos[x]; g[x_] := c*Sin[x] Plot[{f[x], g[x]}, {x, -1, 2}, {AxesOrigin -> {0, 0}}] r = x /. FindRoot[f[x] == g[x], {x, .79, .80}, WorkingPrecision -> 110] RealDigits[r] (* A199742 *)
Extensions
Name corrected by Sean A. Irvine, Jan 12 2025
Comments