Definition:Dottie Number

Definition
The Dottie number $\d$ is defined as the unique fixed point of the cosine function:
 * $\cos \rd = \d$

Its approximate value is given by:
 * $\d \approx 0 \cdotp 73908 \, 51332 \, 15160 \, 64165 \, 53120 \, 87673 \ldots$

Also see

 * Existence and Uniqueness of Dottie Number


 * Dottie Number is Universally Attractive

Source of Name
The name Dottie is of no mathematical significance.

It refers to a professor of French who noticed that if she took the cosine of seemingly any number repeatedly, the result would always converge to the value $0.73908 \ldots$