[Transfer function]

Can someone please help me with this problem:
a) Try to decide the transfer function H(jω) for this:
http://yfrog.com/7cfunknj
vin(t)=Acos(ωt) 
H(jω) =Vout/Vin
I have count that C and R2 to R2/(jωR2C+1)
From here I dont know what to do

b) What is H(jω) if A->∞

thanks in advance