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Revision History for A197140 (Underlined text is an addition; strikethrough text is a deletion.)

Showing all changes.
A197140 Decimal expansion of the x-intercept of the shortest segment from the x axis through (1,1) to the line y=2x.
(history; published version)
#9 by R. J. Mathar at Tue Nov 08 12:14:56 EST 2022
STATUS

editing

approved

#8 by R. J. Mathar at Tue Nov 08 12:14:51 EST 2022
COMMENTS

A root of the polynomial 2*x^3-4*x^2+3*x-2. - R. J. Mathar, Nov 08 2022

#7 by R. J. Mathar at Tue Nov 08 11:31:36 EST 2022
DATA

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

EXTENSIONS

Incorrect trailing digits removed. - R. J. Mathar, Nov 08 2022

STATUS

approved

editing

#6 by Russ Cox at Fri Mar 30 18:57:52 EDT 2012
AUTHOR

_Clark Kimberling (ck6(AT)evansville.edu), _, Oct 11 2011

Discussion
Fri Mar 30 18:57
OEIS Server: https://oeis.org/edit/global/285
#5 by T. D. Noe at Tue Oct 11 15:27:16 EDT 2011
STATUS

proposed

approved

#4 by Clark Kimberling at Tue Oct 11 15:21:13 EDT 2011
STATUS

editing

proposed

#3 by Clark Kimberling at Tue Oct 11 12:32:37 EDT 2011
MATHEMATICA

N[m*k*t/(k + m*t - m*h)]} (* endpt. on line y=2x *)

ContourPlot[(x - h)^2 + (y - k)^2 == .001, {x, 0, 4}, {y, 0, 3}], PlotRange -> {0, 1.7}, AspectRatio -> Automatic]

CROSSREFS

Cf. A197032, A197041A197141, A197008, A195284.

#2 by Clark Kimberling at Tue Oct 11 11:42:38 EDT 2011
NAME

allocatedDecimal expansion of the x-intercept of the shortest segment from the x axis through (1,1) to forthe Clarkline Kimberlingy=2x.

DATA

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

OFFSET

1,2

COMMENTS

The shortest segment from one side of an angle T through a point P inside T is called the Philo line of P in T. For discussions and guides to related sequences, see A197032, A197008 and A195284.

EXAMPLE

length of Philo line: 1.6736473041529...; see A197139

endpoint on x axis: (1.44062, 0)

endpoint on line y=2x: (0.765782, 1.53156)

MATHEMATICA

f[t_] := (t - k*t/(k + m*t - m*h))^2 + (m*k*t/(k + m*t - m*h))^2;

g[t_] := D[f[t], t]; Factor[g[t]]

p[t_] := h^2 k + k^3 - h^3 m - h k^2 m - 3 h k t + 3 h^2 m t + 2 k t^2 - 3 h m t^2 + m t^3 m = 2; h = 1; k = 1; (* slope m, point (h, k) *)

t = t1 /. FindRoot[p[t1] == 0, {t1, 1, 2}, WorkingPrecision -> 100]

RealDigits[t] (* A197140 *)

{N[t], 0} (* endpoint on x axis *)

{N[k*t/(k + m*t - m*h)],

N[m*k*t/(k + m*t - m*h)]} (* endpt. on line y=2x *)

d = N[Sqrt[f[t]], 100]

RealDigits[d] (* A197141 *)

Show[Plot[{k*(x - t)/(h - t), m*x}, {x, 0, 2}],

ContourPlot[(x - h)^2 + (y - k)^2 == .001, {x, 0, 4}, {y, 0, 3}], PlotRange -> {0, 1.7}, AspectRatio -> Automatic]

CROSSREFS

Cf. A197032, A197041, A197008, A195284.

KEYWORD

allocated

nonn,cons

AUTHOR

Clark Kimberling (ck6(AT)evansville.edu), Oct 11 2011

STATUS

approved

editing

#1 by Clark Kimberling at Mon Oct 10 19:42:39 EDT 2011
NAME

allocated for Clark Kimberling

KEYWORD

allocated

STATUS

approved

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Last modified August 29 11:15 EDT 2024. Contains 375512 sequences. (Running on oeis4.)