Anger function
From specialfunctionswiki
The Anger function is defined by $$\mathbf{J}_{\nu}(z) = \dfrac{1}{\pi} \displaystyle\int_0^{\pi} \cos(\nu \theta - z \sin(\theta)) d\theta.$$
Properties
Theorem
The following formula holds for integer $n$: $$\mathbf{J}_n(z)=J_n(z),$$ where $\mathbf{J}_n$ denotes an Anger function and $J_n$ denotes a Bessel function of the first kind.
