The On-Line Encyclopedia of Integer Sequences (OEIS)

A197811 revision #3

A197811

Decimal expansion of x<0 having x^2+x=3*cos(x).

1, 3, 8, 9, 4, 3, 7, 4, 5, 2, 7, 0, 4, 8, 2, 8, 3, 8, 9, 2, 9, 1, 4, 9, 8, 2, 5, 1, 4, 2, 9, 1, 8, 9, 2, 5, 5, 9, 6, 3, 3, 7, 3, 5, 7, 5, 8, 4, 7, 5, 0, 8, 3, 7, 1, 4, 1, 5, 6, 7, 2, 2, 7, 2, 9, 3, 7, 0, 4, 8, 1, 2, 4, 4, 7, 1, 1, 8, 9, 3, 8, 8, 4, 3, 6, 2, 8, 7, 1, 0, 6, 3, 1, 1, 2, 3, 7, 7, 6

(list; constant; graph; refs; listen; history; text; internal format)

OFFSET

1,2

COMMENTS

See A197737 for a guide to related sequences. The Mathematica program includes a graph.

LINKS

Table of n, a(n) for n=1..99.

EXAMPLE

negative: -1.38943745270482838929149825142918925596337...

positive: 0.9297344303618125096887004946976108824038...

MATHEMATICA

a = 1; b = 1; c = 3;

f[x_] := a*x^2 + b*x; g[x_] := c*Cos[x]

Plot[{f[x], g[x]}, {x, -2, 1.5}]

r1 = x /. FindRoot[f[x] == g[x], {x, -1.4, -1.3}, WorkingPrecision -> 110]

RealDigits[r1] (* A197811 *)

r2 = x /. FindRoot[f[x] == g[x], {x, .92, .93}, WorkingPrecision -> 110]

RealDigits[r2] (* A197812 *)

CROSSREFS

Cf. A197737.

Sequence in context: A016672 A177272 A010630 * * A277827 A011276

Adjacent sequences: A197808 A197809 A197810 * A197812 A197813 A197814

KEYWORD

nonn,cons

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu), Oct 20 2011

STATUS

proposed