Exercise 6.7 Does this filter something?

The figure below shows a filter circuit with an opamp.

a)

For this question, assume that for the opamp $r_{\mathit{in}}\to \infty$. The gain of the opamp is finite and frequency dependent. The opamp is unity gain stable.

Describe what it means that the opamp is unity gain stable.

b)

With the same assumptions for the opamp, is the circuit stable or not stable?

c)

Derive an expression for the signal transfer $H(\mathit{j\omega })$ of the circuit . For this question, please assume an ideal opamp; assume $R_2=R_3$.

d)

Draw the Bode plot of the transfer (modulus and phase).