Q-cos sub q
From specialfunctionswiki
The function $\cos_q$ is defined for $|z|<1$ by $$\cos_q(z)=\dfrac{e_q(iz)+e_q(-iz)}{2},$$ where $e_q$ denotes the $q$-exponential $e$ and $(q;q)_{2k}$ denotes the $q$-Pochhammer symbol.
Properties
External links
References
- 2012: Thomas Ernst: A Comprehensive Treatment of q-Calculus ... (previous): $(6.202)$