The smallest positive solution to a trigonometric equation












0












$begingroup$


I'm trying to determine the order of growth of the function



begin{align*}
k mapsto min lbrace s > 0 : 2cdot cos(tfrac{s}{2})^{2(k-2)} - sin(tfrac{s}{2}) - 1 = 0 rbrace, quad k geqslant 3 text{ an integer.}
end{align*}

However, I must say that I'm not really sure how to even begin... Any thoughts on this?



Motivation: In relation to a project I'm working on, I'm trying to understand the images $Omega_k$ of a certain family of maps



begin{align*}
J_k : (0, pi)^{{k}choose{2}} rightarrow (0, pi)^{{k}choose{2}},
end{align*}

mapping a bunch of angles to another bunch of angles. (I'll spare you the details as they're not much to look at...) The question above turns out to be related to the existence of some nice sets (i.e. cubes) inside the quite strange-looking $Omega_k$.










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$endgroup$












  • $begingroup$
    Notation is not clear. Is it $cos(a^b)$ or $(cos(a))^b$?
    $endgroup$
    – Andrei
    Jan 24 at 16:43










  • $begingroup$
    It's $(cos(a))^b$.
    $endgroup$
    – Teddan the Terran
    Jan 24 at 16:55
















0












$begingroup$


I'm trying to determine the order of growth of the function



begin{align*}
k mapsto min lbrace s > 0 : 2cdot cos(tfrac{s}{2})^{2(k-2)} - sin(tfrac{s}{2}) - 1 = 0 rbrace, quad k geqslant 3 text{ an integer.}
end{align*}

However, I must say that I'm not really sure how to even begin... Any thoughts on this?



Motivation: In relation to a project I'm working on, I'm trying to understand the images $Omega_k$ of a certain family of maps



begin{align*}
J_k : (0, pi)^{{k}choose{2}} rightarrow (0, pi)^{{k}choose{2}},
end{align*}

mapping a bunch of angles to another bunch of angles. (I'll spare you the details as they're not much to look at...) The question above turns out to be related to the existence of some nice sets (i.e. cubes) inside the quite strange-looking $Omega_k$.










share|cite|improve this question









$endgroup$












  • $begingroup$
    Notation is not clear. Is it $cos(a^b)$ or $(cos(a))^b$?
    $endgroup$
    – Andrei
    Jan 24 at 16:43










  • $begingroup$
    It's $(cos(a))^b$.
    $endgroup$
    – Teddan the Terran
    Jan 24 at 16:55














0












0








0





$begingroup$


I'm trying to determine the order of growth of the function



begin{align*}
k mapsto min lbrace s > 0 : 2cdot cos(tfrac{s}{2})^{2(k-2)} - sin(tfrac{s}{2}) - 1 = 0 rbrace, quad k geqslant 3 text{ an integer.}
end{align*}

However, I must say that I'm not really sure how to even begin... Any thoughts on this?



Motivation: In relation to a project I'm working on, I'm trying to understand the images $Omega_k$ of a certain family of maps



begin{align*}
J_k : (0, pi)^{{k}choose{2}} rightarrow (0, pi)^{{k}choose{2}},
end{align*}

mapping a bunch of angles to another bunch of angles. (I'll spare you the details as they're not much to look at...) The question above turns out to be related to the existence of some nice sets (i.e. cubes) inside the quite strange-looking $Omega_k$.










share|cite|improve this question









$endgroup$




I'm trying to determine the order of growth of the function



begin{align*}
k mapsto min lbrace s > 0 : 2cdot cos(tfrac{s}{2})^{2(k-2)} - sin(tfrac{s}{2}) - 1 = 0 rbrace, quad k geqslant 3 text{ an integer.}
end{align*}

However, I must say that I'm not really sure how to even begin... Any thoughts on this?



Motivation: In relation to a project I'm working on, I'm trying to understand the images $Omega_k$ of a certain family of maps



begin{align*}
J_k : (0, pi)^{{k}choose{2}} rightarrow (0, pi)^{{k}choose{2}},
end{align*}

mapping a bunch of angles to another bunch of angles. (I'll spare you the details as they're not much to look at...) The question above turns out to be related to the existence of some nice sets (i.e. cubes) inside the quite strange-looking $Omega_k$.







trigonometry






share|cite|improve this question













share|cite|improve this question











share|cite|improve this question




share|cite|improve this question










asked Jan 24 at 16:30









Teddan the TerranTeddan the Terran

1,206210




1,206210












  • $begingroup$
    Notation is not clear. Is it $cos(a^b)$ or $(cos(a))^b$?
    $endgroup$
    – Andrei
    Jan 24 at 16:43










  • $begingroup$
    It's $(cos(a))^b$.
    $endgroup$
    – Teddan the Terran
    Jan 24 at 16:55


















  • $begingroup$
    Notation is not clear. Is it $cos(a^b)$ or $(cos(a))^b$?
    $endgroup$
    – Andrei
    Jan 24 at 16:43










  • $begingroup$
    It's $(cos(a))^b$.
    $endgroup$
    – Teddan the Terran
    Jan 24 at 16:55
















$begingroup$
Notation is not clear. Is it $cos(a^b)$ or $(cos(a))^b$?
$endgroup$
– Andrei
Jan 24 at 16:43




$begingroup$
Notation is not clear. Is it $cos(a^b)$ or $(cos(a))^b$?
$endgroup$
– Andrei
Jan 24 at 16:43












$begingroup$
It's $(cos(a))^b$.
$endgroup$
– Teddan the Terran
Jan 24 at 16:55




$begingroup$
It's $(cos(a))^b$.
$endgroup$
– Teddan the Terran
Jan 24 at 16:55










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