login

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

A197260
Decimal expansion of least x>0 having sin(3x) = sin(x)^2.
2
8, 4, 8, 0, 6, 2, 0, 7, 8, 9, 8, 1, 4, 8, 1, 0, 0, 8, 0, 5, 2, 9, 4, 4, 3, 3, 8, 9, 9, 8, 4, 1, 8, 0, 8, 0, 0, 7, 3, 3, 6, 6, 2, 1, 3, 2, 6, 3, 1, 1, 2, 6, 4, 2, 8, 6, 0, 7, 1, 8, 1, 6, 3, 5, 7, 0, 2, 0, 0, 8, 2, 1, 2, 2, 8, 4, 7, 4, 2, 3, 4, 3, 4, 9, 1, 8, 9, 8, 0, 1, 7, 3, 1, 9, 5, 7, 2, 3, 0, 3
OFFSET
0,1
COMMENTS
The Mathematica program includes a graph. See A197133 for a guide to least x>0 satisfying sin(b*x)=(sin(c*x))^2 for selected b and c.
FORMULA
Equals arcsin(3/4). - Alexandru Petrescu, Jul 08 2024
Equals 2*A197291 = A197377/3. - Hugo Pfoertner, Jul 08 2024
EXAMPLE
0.84806207898148100805294433899841808007...
MATHEMATICA
b = 3; c = 1; f[x_] := Sin[x]
t = x /. FindRoot[f[b*x] == f[c*x]^2, {x, .6, 1}, WorkingPrecision -> 100]
RealDigits[t] (* this sequence *)
Plot[{f[b*x], f[c*x]^2}, {x, 0, Pi}]
RealDigits[ ArcCos[ Sqrt[7]/4], 10, 100] // First (* Jean-François Alcover, Feb 19 2013 *)
CROSSREFS
KEYWORD
nonn,cons
AUTHOR
Clark Kimberling, Oct 12 2011
STATUS
approved