login
The OEIS is supported by the many generous donors to the OEIS Foundation.

 

Logo
Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A201416 Decimal expansion of least x satisfying 7*x^2 = sec(x) and 0 < x < Pi. 3

%I #8 Apr 10 2021 08:07:01

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

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

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

%N Decimal expansion of least x satisfying 7*x^2 = sec(x) and 0 < x < Pi.

%C See A201397 for a guide to related sequences. The Mathematica program includes a graph.

%e least: 0.39327382732884150383245205720625342659...

%e greatest: 1.507928795380098266567899994070991413...

%t a = 7; c = 0;

%t f[x_] := a*x^2 + c; g[x_] := Sec[x]

%t Plot[{f[x], g[x]}, {x, 0, Pi/2}, {AxesOrigin -> {0, 0}}]

%t r = x /. FindRoot[f[x] == g[x], {x, .3, .4}, WorkingPrecision -> 110]

%t RealDigits[r] (* A201416 *)

%t r = x /. FindRoot[f[x] == g[x], {x, 1.5, 1.6}, WorkingPrecision -> 110]

%t RealDigits[r] (* A201417 *)

%Y Cf. A201397.

%K nonn,cons

%O 0,1

%A _Clark Kimberling_, Dec 01 2011

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recents
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified April 23 14:49 EDT 2024. Contains 371914 sequences. (Running on oeis4.)