cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-12 of 12 results.

A332526 Decimal expansion of the minimal distance between distinct branches of the tangent function; see Comments.

Original entry on oeis.org

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

Views

Author

Clark Kimberling, Jun 15 2020

Keywords

Comments

Let T0 and T1 be the branches of the graph of y = tan x that passes through (0,0,) and (Pi,0), respectively. There exist points P = (p,q) on T0 and U = (u,v) on T1 such that the distance between P and U is the minimal distance, d, between points on T0 and T1.
u = 2.549082584017596768984130292562154758705824602711...
v = -0.67319711901285205370684801604861382107848678888...
p = Pi - u
q = - v
d = 2.375069146040176349439851558778982487866267806508...

Examples

			minimal distance = 2.375069146040176349439851558778982487866267806508...
		

Crossrefs

Programs

  • Mathematica
    min = Quiet[FindMinimum[Sqrt[(#[[1]][[1]] - #[[2]][[1]])^2 + (#[[1]][[2]] - \
    #[[2]][[2]])^2] &[{{#, Tan[#]} &[x /. FindRoot[# Cos[#]^2 - x Cos[#]^2 + Tan[#] == Tan[x], {x, 0}, WorkingPrecision -> 500]], {#, Tan[#]} &[#]} &[y]], {y, 2}, WorkingPrecision -> 100]]
    Show[Plot[{Tan[x], (-# Sec[#]^2) + x Sec[#]^2 + Tan[#], {(# Cos[#]^2) - x Cos[#]^2 + Tan[#]}}, {x, 0, Pi}, AspectRatio -> Automatic, ImageSize -> 300, PlotRange -> {-2, 2}], Graphics[{PointSize[Large], Point[{Pi/2, 0}], Point[{#, Tan[#]}], Point[{Pi - #, -Tan[#]}]}]] &[y /. min[[2]][[1]]]
    (* Peter J. C. Moses, May 06 2020 *)

A332522 Decimal expansion of the number u such that the line normal to the graph of y = sin x at (u, sin u) passes through (Pi/4,0).

Original entry on oeis.org

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

Views

Author

Clark Kimberling, May 05 2020

Keywords

Examples

			u = 0.4158555967898679887880048019...
		

Crossrefs

Programs

  • Mathematica
    u = u /. FindRoot[0 == (-Pi/4) Sec[u] + u Sec[u] + Sin[u], {u, 0}, WorkingPrecision ->  150]
    RealDigits[u][[1]]
Previous Showing 11-12 of 12 results.