A215670 - OEIS

A215670

Decimal expansion of the min value of F(x) := cos(sin(x)) - sin(cos(x)), x in R.

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

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OFFSET

0,3

COMMENTS

We note that dF(x)/dx = (-1/2)*h(x)*sin(2*x), x in (0,Pi/2), where h(x) is the function discussed in comments to A215668 (see also Witula et al.'s reference for more informations).

REFERENCES

R. Witula, D. Jama, E. Hetmaniok, D. Slota, On some inequality of the trigonometric type, Zeszyty Naukowe Politechniki Slaskiej - Matematyka-Fizyka (Science Fascicle of Silesian Technical University - Math.-Phys.), 92 (2010), 83-92.

LINKS

Table of n, a(n) for n=0..103.

FORMULA

F(z) = cos(sin(z)) - sin(cos(z)) = (cos(z) - sin(z))*(cos(cos(z)) + sin(sin(z)))*cos(cos(z))/(cos(sin(z)) + sin(cos(z)))*cos(z) = cos(2*z)*cos(cos(z))^2/(cos(sin(z)) + sin(cos(z)))*cos(z)^2 = (1 - tan(z)^2)*cos(cos(z))^2/(cos(sin(z)) + sin(cos(z))), where z := A215668.

EXAMPLE

min{F(x): x in R} = F(z) = 0.1071269448729529961...

CROSSREFS

Cf. A215668, A215832, A215833, A168546, A216891.

Sequence in context: A147708 A238273 A155773 * A010144 A195409 A318353

Adjacent sequences: A215667 A215668 A215669 * A215671 A215672 A215673

KEYWORD

nonn,cons

AUTHOR

Roman Witula, Aug 20 2012

STATUS

approved