We consider generalized *-derivations on C^*-algebra and we will first study the conditions for a linear generalized *-derivation on C^*-algebra. Then we prove some theorems involving approximate linear generalized *-derivations on C^*-algebra. So approximate linear generalized *-derivations on C^*-algebra are characterized.

We establish the general solution for a mixed type functional equation of aquartic and a quadratic mapping in linear spaces. In addition, we investigate the generalized Hyers‐Ulam stability in p‐Banach spaces.