To save for retirement, Ed is investing 12:553 thousand dollars this yoar. Write the function Rt) that shows the stream of money flowing into Ed's investment account inder each of the following circumstances. Assume a continuous income stream. Do NOT round any values. (a) Ed continues to Invest the same amount each year for the next 20 years. R() thousand dollars per year (b) Ed increases his investment by 4.23 thousand dollars per year over the next 20 year thousand dollars per year (e) Ed increases his investment ty 4.23% each year ever the next 20 years thousand doliars per year