A198130 Decimal expansion of least x having 2*x^2+3*x=2*cos(x), negated.

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.

Links

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

Index entries for transcendental numbers.

Example

least x: -1.52799971203684063352083669388890466...
greatest x: 0.458061086830838048904156490023125...

Maple

Digits:=120:
fsolve(2*x^2-3*x-2*cos(x), x=1.5);  # Alois P. Heinz, Apr 14 2026

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 *)

Prog

(PARI) solve(x=-2, -1, 2*x^2+3*x-2*cos(x)) \\ Charles R Greathouse IV, Apr 14 2026

Crossrefs

Cf. A197737.

Sequence in context: A201423 A155790 A200646 * A309773 A241388 A305574

Adjacent sequences: A198127 A198128 A198129 * A198131 A198132 A198133

Keyword

nonn,cons

Author

Clark Kimberling, Oct 22 2011

Extensions

Name corrected by Charles R Greathouse IV, Apr 14 2026

Status

approved