Final answer:
The Federal Reserve's creation of bank reserves shifts the supply curve of bank reserves rightward, with an intersection point on the demand curve at the current federal funds rate of 0.2%. If further purchases don't alter the rate, the demand curve shows perfectly elastic demand at that rate.
Step-by-step explanation:
The question involves the Federal Reserve's (Fed) use of monetary policy tools to influence the supply and demand for bank reserves, which in turn affects the federal funds rate. When the Fed creates $3 trillion of bank reserves, it's executing an open market purchase to increase liquidity in the banking system. This action would shift the supply curve for bank reserves, labeled as RS, to the right. Demand for bank reserves, labeled as RD, is downward sloping because banks will want to hold more reserves when the federal funds rate is lower, hence the quantity of reserves demanded increases when the rate falls.
If an additional open market purchase does not change the federal funds rate, the demand curve would demonstrate perfectly elastic demand at the current federal funds rate of 0.2%. The equilibrium point would be located where the supply and demand curves intersect at the 0.2% federal funds rate, thereby illustrating the equilibrium quantity of reserves demanded and supplied at this interest rate.