Capacitor Exercise (09-08-2020)

The gap between the plates of a parallel plate capacitor is filled with isotropic dielectric whose permittivity $\epsilon$ varies linearly from $\epsilon_{1}$ to $\epsilon_{2}$ $(\epsilon_{2}> \epsilon_{1} )$ in the direction perpendicular to the plates.
The area of each plates equals $S$ , the separation between the plates is equal to $d$ .
Find the space density of the bound charges as a function of $\epsilon$ if the charge of the capacitor is q and the field $E$
in it is directing toward the growing $\epsilon$ value.

The answers comes in the form of $\frac{\alpha q(\epsilon_{2}- \epsilon_{1})^{\beta} }{Sd \epsilon^{\gamma}}$
Then type your answer as $\alpha+\beta+\gamma=?$