A196816 Decimal expansion of the least x>0 satisfying 1/(1+x^2)=cos(x).

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

Offset

1,4

Links

Table of n, a(n) for n=1..100.

Eric Weisstein's World of Mathematics, Witch of Agnesi

Example

x=1.10250582440641604357105015502222407388481058200...

Mathematica

Plot[{1/(1 + x^2), Cos[x], 2 Cos[x], 3 Cos[x], 4 Cos[x]}, {x, 0, 2}]
t = x /. FindRoot[1 == (1 + x^2) Cos[x], {x, 1, 1.5}, WorkingPrecision -> 100]
RealDigits[t]

Prog

(PARI) solve(x=1, 1.5, cos(x)*(1+x^2) - 1) \\ Michel Marcus, Feb 10 2015

Crossrefs

Cf. A196914, A196817, A196818, A196819, A196820, A196821.

Sequence in context: A307649 A024714 A123342 * A058204 A242969 A268886

Adjacent sequences: A196813 A196814 A196815 * A196817 A196818 A196819

Keyword

nonn,cons

Author

Clark Kimberling, Oct 06 2011

Status

approved