A196398 Decimal expansion of the positive number x satisfying e^x=4*cos(x).

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

Offset

0,1

Links

Table of n, a(n) for n=0..100.

Example

0.90478821787301885347402135993704348827...

Mathematica

Plot[{E^x, 2 Cos[x], 3 Cos[x], 4 Cos[x]}, {x, 0, Pi/2}]
t = x /.
  FindRoot[E^x == 2 Cos[x], {x, .5, .6}, WorkingPrecision -> 100]; RealDigits[t]  (* A196396 *)
t = x /.
  FindRoot[E^x == 3 Cos[x], {x, .7, .8}, WorkingPrecision -> 100]; RealDigits[t]  (* A196397 *)
t = x /.
  FindRoot[E^x == 4 Cos[x], {x, .8, 1.0}, WorkingPrecision -> 100]; RealDigits[t]  (* A196398 *)
t = x /.
  FindRoot[E^x == 5 Cos[x], {x, .8, 1.0}, WorkingPrecision -> 100]; RealDigits[t]  (* A196399 *)
t = x /.
  FindRoot[E^x == 6 Cos[x], {x, 1.0, 1.1}, WorkingPrecision -> 100]; RealDigits[t]  (* A196400 *)

Crossrefs

Sequence in context: A195692 A021088 A021529 * A192932 A361061 A301865

Adjacent sequences: A196395 A196396 A196397 * A196399 A196400 A196401

Keyword

nonn,cons

Author

Clark Kimberling, Oct 02 2011

Extensions

a(100) corrected by Georg Fischer, Jul 30 2021

Status

approved