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”).

A198130
Decimal expansion of least x having 2*x^2+3x=2*cos(x).
3
1, 5, 2, 7, 9, 9, 9, 7, 1, 2, 0, 3, 6, 8, 4, 0, 6, 3, 3, 5, 2, 0, 8, 3, 6, 6, 9, 3, 8, 8, 8, 9, 0, 4, 6, 6, 3, 6, 7, 6, 3, 7, 5, 9, 3, 9, 9, 4, 1, 6, 2, 5, 9, 9, 2, 0, 8, 7, 2, 7, 8, 7, 3, 2, 5, 4, 0, 3, 7, 9, 1, 6, 5, 3, 5, 9, 8, 1, 0, 2, 5, 1, 2, 5, 7, 5, 0, 2, 9, 4, 2, 8, 6, 0, 8, 7, 8, 9, 6
OFFSET
1,2
COMMENTS
See A197737 for a guide to related sequences. The Mathematica program includes a graph.
EXAMPLE
least x: -1.52799971203684063352083669388890466...
greatest x: 0.458061086830838048904156490023125...
MATHEMATICA
a = 2; b = 3; c = 2;
f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]
Plot[{f[x], g[x]}, {x, -2, 1}]
r1 = x /. FindRoot[f[x] == g[x], {x, -1.53, -1.52}, WorkingPrecision -> 110]
RealDigits[r1](* A198130 *)
r2 = x /. FindRoot[f[x] == g[x], {x, .45, .46}, WorkingPrecision -> 110]
RealDigits[r2](* A198131 *)
CROSSREFS
Cf. A197737.
Sequence in context: A201423 A155790 A200646 * A309773 A241388 A305574
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Oct 22 2011
STATUS
approved