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A076418 Decimal expansion of second solution of equation cos(x)*cosh(x) = -1. 2

%I

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

%T 0,4,9,3,8,9,8,9,6,7,3,7,5,4,5,7,6,6,8,2,8,9,7,2,8,0,3,2,7,7,8,4,9,0,

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

%N Decimal expansion of second solution of equation cos(x)*cosh(x) = -1.

%C This is an equation related to a cantilever beam: cos(x)*cosh(x) = -1. The first three solutions are: 1.875 (A076417), 4.69409 (this sequence) and 7.854757 (A076419).

%H Z. Guede, I. Elishakov, <a href="http://dx.doi.org/10.1016/S0960-0779(00)00014-X">A fifth-order polynomial that serves as both buckling and vibration mode of an inhomogeneous structure</a>, Chaos, Solitons and Fractals 12 (7) (2001) 1267-1298.

%e 4.694091132974174576436391778...

%t RealDigits[x/.FindRoot[Cos[x]Cosh[x]==-1,{x,4},WorkingPrecision-> 120]] [[1]] (* _Harvey P. Dale_, May 01 2019 *)

%o (PARI) solve(x=4, 5, cos(x)*cosh(x) + 1) \\ _Michel Marcus_, Sep 11 2019

%Y Cf. A076417, A076419.

%K easy,nonn,cons

%O 1,1

%A _Zak Seidov_, Oct 10 2002

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Last modified August 8 09:16 EDT 2020. Contains 336293 sequences. (Running on oeis4.)