A197847 Decimal expansion of least x having x^2+2x=4*cos(x).

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

Offset: 1

Author

Clark Kimberling, Oct 20 2011

Keywords

• nonn
• cons

Comments

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

Examples

			least x: -1.6989977519984890831842928796985548...
greatest x: 0.88207436611847498021987395522394374915...
		

Crossrefs

Cf. A197737.

Programs

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 *)