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A197847 Decimal expansion of least x having x^2+2x=4*cos(x). 3
1, 6, 9, 8, 9, 9, 7, 7, 5, 1, 9, 9, 8, 4, 8, 9, 0, 8, 3, 1, 8, 4, 2, 9, 2, 8, 7, 9, 6, 9, 8, 5, 5, 4, 8, 1, 4, 5, 6, 2, 2, 3, 9, 0, 8, 1, 5, 2, 0, 2, 2, 2, 7, 3, 4, 9, 7, 5, 6, 9, 3, 7, 1, 2, 1, 9, 1, 8, 3, 3, 0, 0, 6, 5, 2, 0, 5, 2, 6, 9, 8, 0, 3, 6, 9, 8, 6, 8, 9, 5, 3, 1, 0, 1, 9, 0, 4, 4, 5 (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

least x: -1.6989977519984890831842928796985548...

greatest x: 0.88207436611847498021987395522394374915...

MATHEMATICA

a = 1; b = 2; c = 4;

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, -1.7, -1.6}, WorkingPrecision -> 110]

RealDigits[r1] (* A197847 *)

r2 = x /. FindRoot[f[x] == g[x], {x, .88, .89}, WorkingPrecision -> 110]

RealDigits[r2] (* A197848 *)

CROSSREFS

Cf. A197737.

Sequence in context: A019753 A200105 A153268 * A303046 A155554 A019902

Adjacent sequences:  A197844 A197845 A197846 * A197848 A197849 A197850

KEYWORD

nonn,cons

AUTHOR

Clark Kimberling, Oct 20 2011

STATUS

approved

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Last modified June 2 11:35 EDT 2020. Contains 334771 sequences. (Running on oeis4.)