

A255899


Decimal expansion of Mrs. Miniver's constant.


1



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

0,1


COMMENTS

This constant is the solution to an elementary problem involving two overlapping circles, known as "Mrs. Miniver's problem" (cf. S. R. Finch, p. 487), the value of the solution being the distance between the centers of the two circles (see the picture by L. A. Graham in A192408).


REFERENCES

Steven R. Finch, Mathematical Constants, Cambridge University Press, 2003, p. 487.


LINKS

Table of n, a(n) for n=0..104.
Steven R. Finch, Errata and Addenda to Mathematical Constants, p. 62.


FORMULA

The unique root of the equation 2*arccos(x/2)  (1/2)*x*sqrt(4  x^2) = 2*Pi/3 in the interval [0,2].


EXAMPLE

0.5298641692055537248682329895251421373003801320827289...


MATHEMATICA

d = x /. FindRoot[2*ArcCos[x/2]  (1/2)*x*Sqrt[4  x^2] == 2*Pi/3, {x, 1/2}, WorkingPrecision > 105]; RealDigits[d] // First


PROG

(PARI) solve (x=0, 2, 2*acos(x/2)  (1/2)*x*sqrt(4  x^2)  2*Pi/3) \\ Michel Marcus, Mar 10 2015


CROSSREFS

Cf. A192408.
Sequence in context: A329986 A097897 A063761 * A019841 A064582 A197374
Adjacent sequences: A255896 A255897 A255898 * A255900 A255901 A255902


KEYWORD

nonn,cons,easy


AUTHOR

JeanFrançois Alcover, Mar 10 2015


STATUS

approved



