10 Bessel FunctionsBessel and Hankel Functions

§10.12 Generating Function and Associated Series

For z∈ℂ and t∈ℂ∖{0},

10.12.1 e12⁢z⁢(t−t−1)=∑m=−∞∞tm⁢Jm⁡(z).

Jacobi–Anger expansions: for z,θ∈ℂ,

10.12.2 cos⁡(z⁢sin⁡θ) =J0⁡(z)+2⁢∑k=1∞J2⁢k⁡(z)⁢cos⁡(2⁢k⁢θ),
sin⁡(z⁢sin⁡θ) =2⁢∑k=0∞J2⁢k+1⁡(z)⁢sin⁡((2⁢k+1)⁢θ),
10.12.3 cos⁡(z⁢cos⁡θ) =J0⁡(z)+2⁢∑k=1∞(−1)k⁢J2⁢k⁡(z)⁢cos⁡(2⁢k⁢θ),
sin⁡(z⁢cos⁡θ) =2⁢∑k=0∞(−1)k⁢J2⁢k+1⁡(z)⁢cos⁡((2⁢k+1)⁢θ).
10.12.4 1=J0⁡(z)+2⁢J2⁡(z)+2⁢J4⁡(z)+2⁢J6⁡(z)+⋯,
10.12.5 cos⁡z =J0⁡(z)−2⁢J2⁡(z)+2⁢J4⁡(z)−2⁢J6⁡(z)+⋯,
sin⁡z =2⁢J1⁡(z)−2⁢J3⁡(z)+2⁢J5⁡(z)−⋯,
10.12.6 12⁢z⁢cos⁡z =J1⁡(z)−9⁢J3⁡(z)+25⁢J5⁡(z)−49⁢J7⁡(z)+⋯,
12⁢z⁢sin⁡z =4⁢J2⁡(z)−16⁢J4⁡(z)+36⁢J6⁡(z)−⋯.