\(C _{ eq }=\frac{2 \epsilon_{0}}{3 d } \times\left(2 \times \frac{3}{2}\right)=2\left(\because A =1 b =2 \times \frac{3}{2}\right)\)
$\varepsilon(x)=\varepsilon_{0}+k x, \text { for }\left(0\,<\,x \leq \frac{d}{2}\right)$
$\varepsilon(x)=\varepsilon_{0}+k(d-x)$, for $\left(\frac{d}{2} \leq x \leq d\right)$