login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A197820
Decimal expansion of greatest x having x^2-2x=-cos(x).
3
2, 2, 8, 7, 0, 8, 6, 1, 7, 7, 6, 5, 6, 5, 8, 4, 4, 8, 5, 3, 3, 7, 0, 3, 3, 3, 1, 2, 3, 1, 4, 4, 9, 1, 7, 3, 7, 3, 9, 5, 7, 8, 2, 0, 7, 5, 1, 2, 9, 2, 3, 9, 8, 4, 0, 8, 2, 9, 0, 8, 4, 3, 9, 0, 0, 4, 0, 1, 4, 3, 0, 8, 6, 4, 7, 9, 6, 9, 0, 1, 9, 2, 9, 0, 5, 6, 0, 3, 8, 9, 1, 5, 4, 1, 4, 4, 7, 3, 8
OFFSET
1,1
COMMENTS
See A197737 for a guide to related sequences. The Mathematica program includes a graph.
EXAMPLE
least x: 0.589303208159012874725223919073869185889...
greatest x: 2.287086177656584485337033312314491737...
MATHEMATICA
a = 1; b = -2; c = -1;
f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
Plot[{f[x], g[x]}, {x, -1, 3}]
r1 = x /. FindRoot[f[x] == g[x], {x, .5, .6}, WorkingPrecision -> 110]
RealDigits[r1] (* A197815 *)
r2 = x /. FindRoot[f[x] == g[x], {x, 2.2, 2.3}, WorkingPrecision -> 110]
RealDigits[r2] (* A197820 *)
CROSSREFS
Cf. A197737.
Sequence in context: A353268 A245582 A361790 * A064862 A123202 A195299
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Oct 20 2011
STATUS
approved